Out Now: Voyager

Voyager is now available to download on the Windows Phone Marketplace!

Get it today (it’s absolutely free), and be among the first to play what some are calling “The smartest game about flinging things at things since Angry Birds: The College Years. Oh, that’s not a thing? Yeah, this is the smartest one, then.”

Announcing Voyager

35 years ago this week, Voyager 1 was launched by NASA to explore the outer Solar System. In honor of one of the most successful scientific expeditions of all time, I am proud to announce Voyager, the next game from Rumor Games.


As an engineer in charge of the Voyager space probe, your job is to carefully aim your launch to avoid obstacles, gravitationally slingshot around planets, and get close enough to your target to scan it – without crashing into it!

  • 20+ challenging levels spread across a Grand Tour of the Solar System
  • Take and share pictures of the planets you’ve explored
  • Online scoreboards powered by Scoreloop

Coming soon for Windows Phone.

The Worse Bug

Rare Earth is not profitable. Let’s get that out of the way up-front. The game was released as an experiment to see whether the mobile games platform would be receptive to an unfinished (but frequently-updated) game concept. In many ways, the experiment was a failure. Users were extremely divided about playing an unfinished product (almost all the reviews were either 5 stars or 1 star), and there were nowhere near enough users to generate enough impressions to make any money off the game. Or so I thought.

Here’s a graph of my impressions for June and much of July. Rare Earth is just one of the pack among the 3 ad units from BuildDown:

However, when I was finalizing the latest Rare Earth release (v0.6), I noticed an oversight on my part.  had programmed logic into my ad control wrapper to detect errors, wait a bit, and try to recreate the ad control, in an attempt to recover from any crashing issues in Microsoft’s ad control. Unfortunately, I had forgotten a critical component – to actually call my update logic! Ultimately, any ad crash caused the ad control to stop functioning until the game was started up anew. I had no idea I was missing out on potential impressions until I fixed the bug. Here’s the same chart, with another two weeks added in:

Well that’s interesting. Flurry tells me there hasn’t been any significant uptick in my userbase or number of sessions. Isolating for the variable, that means I have a 5-20x upgrade in my number of impressions just by compensating for errors in Microsoft’s ad control! Extrapolating backward, Rare Earth could have been sitting on hundreds of thousands more impressions over the two months it’s been live.

I’m sure there’s a lesson in there somewhere.


Now that Rare Earth has been out for a few months, I’d like to take a look at some of the data that’s been gathered from players, as well as reflect on the implications.

Analytics have been a big part of the Rare Earth experiment. I used Flurry for this. It was incredibly easy to implement (they actually have a Windows Phone SDK!) and free.

That said, the service isn’t perfect. For example, according to Flurry, 6308 people have downloaded Rare Earth. Microsoft’s App Hub statistics say the number is 10617. Assuming Microsoft is right, since they control the servers and all, Flurry is missing a full 40% of users.

Even so, the numbers should be good enough to draw some conclusions. Let’s get started!


Between 6308 users and 1503 new games, 7811 solar systems have been created

A reported 16660 play sessions

15478 new planets have been created

9359 planets were consumed by stars (judging by some reviews, this often wasn’t intentional!)

79211 asteroid waves have entered, as well as 105450 comets

4840 star upgrades have been purchased

56 stars have reached the end of their lives (version 0.6 introduced stellar evolution, and has only been live for a few days)


379 users have discovered life, and have nurtured its existence on 1024 planets

Beyond the initial required spark to the single-cell organism stage, users have also used the spark to shortcut to:

  • Plant-level 289 times
  • Animal-level 368 times
  • City-level 360 times
  • Space-faring-level 251 times

Curious that people generally skip forward in the middle stages most, rather than the highest level (which takes the most time to advance naturally)

2702 gamma ray bursts have torn through systems with life

1819 of those GRBs have caused mass extinctions

In other words, 67% of GRBs were fatal, which indicates the difficulty for this obstacle is quite high. I’ve received this feedback independently from several players, but this data really crystallizes that

3170 rockets have been launched from space-faring planets (about half of which were planet evacuations)

Only 275 have successfully landed and colonized planets (~9%; perhaps space-faring life is due for an intelligence upgrade?)


6113 orbits have been normalized (a surprisingly popular feature – maybe the standard controls could use with a bit of “assist” if the difficulty is so high that people happily trade valuable earned orbits for more-stable planet orbits?)

A dismal 11 people have clicked on the referral for BuildDown. Is the game not appealing to those in the market for a gravity/life sim/arcade game? Or do people just ignore the About menu? Actually, I can’t tell. I didn’t hook menu transitions, so I don’t have the data to answer that question. Big oversight, and lesson learned for next time!


34101 invaders have made their way into systems

8594 were shot down

I figured a fair number of kills were accidental, as invaders in early versions used to get tripped up around stars and crash themselves.
However, since they were upgraded to avoid stars a few versions ago, the kill rate has actually improved, which shows that the only thing holding players back before was their enemies’ own stupidity

Before the feature was removed, 9383 “orbits for matter” transactions occurred. While a popular option, ultimately it hurt balancing for other orbit-powered features, like life and orbit normalization. Instead, I’m trying other ways of making more matter available to players

The email feedback button was pushed 211 times (my inbox says 72 people went through with it, and I really appreciate all that incredible feedback!)

Even with the inaccuracies, these analytics have been very helpful, providing another dimension of insight to complement the impressive volume of marketplace reviews and feedback emails.

The Bug

Start new game. Exit game. Resume game.
Expected result: Game resumes where player left off.
Actual result: Camera appears stuck inside sun OR game crashes

After Rare Earth 0.1 was released, it wasn’t long before the first bug reports started rolling in. This issue bubbled to the top quickly. However, I was just about to leave on a trip to Europe and only had time for one quick update to the game, so I instead addressed the bug that was getting the most complaints and added instructions.

Maybe being immersed in foreign cultures gave me the idea, but as soon as I got back, the first thing I tried was to change the region format on my phone. Sure enough, I could suddenly repro the bug. Why should the region format matter? Math is the same in any language, and all the game UI treats numbers as invariant culture, specifically to avoid issues like this.

Ah, but I overlooked another point of vulnerability – the game save. Each object in the game is serialized as a collection of XML attributes: mass, radius, etc. For example, a sphere looks like this:

var element = new XElement("Sphere");
element.Add(new XAttribute("Radius", body.Radius));

…where Body includes universal physics properties, like position and mass. Loading is a bit more nuanced, but ultimately ends up with something like this:

var radius = float.Parse(xAttribute.Value);

This would work fine, if creating an XML attribute and parsing a float defaulted to the same culture format (either both current or both invariant). But if they did, this post wouldn’t exist. My saved attributes always had floats formatted the U.S. English way (e.g. 0.45), but float.Parse apparently defaults to the current culture. In a region format like Italian, 0.45 reads like 0,45 would in English – 45 with some junk in front. So a star that was 0.9 units wide at save time is 90 units wide at load time, which is bigger than the entire game world, which means you’re stuck inside the sun forever. Best case scenario. Worst case, some numbers can’t even be parsed, the load operation fails, and now the game crashes every time. Fortunately, there is a pretty simple fix:

float.Parse(xAttribute.Value, CultureInfo.InvariantCulture);

I could alternately serialize my value types to the current culture by hand, but that could have other consequences, so I stuck with the simple fix.

Ultimately, it’s a pretty embarrassing mistake, but I learned a valuable lesson about testing my game for an international audience.

Coming Soon

It’s been a while since the last update, and for that I apologize. I’ve been really busy lately, which unfortunately has set back my schedule for Rare Earth. On the other hand, there’s been plenty of time to gather feedback! This has been incredibly helpful – dozens of players have forwarded crash reports that have helped me track down and fix bugs. In addition, there’s been plenty of analytic data rolling in. For instance, check out this breakdown of feature votes submitted so far:

There’s still a clear demand for improved instruction (even after last update’s stopgap of an info screen), and people would love some customization options, but the clear winner is LIFE. Well, I haven’t wasted any time – it’ll be in the next update!

Opening Weekend

Wow, the initial response to Rare Earth has been incredible. In two days, it’s seen more reviews than BuildDown has in two months. On the other hand, the reviews themselves are heavily divided. Some excerpts:



“What im suppose to do in this game??!=/”

– drumpoke227



“Awesome after you get it what to do >_<”

– AbsurdMr Egg



“Vi prego, aggiungete un manuale di istruzione!”

– Player 401416879


According to Google Translate, that last one says “Please, add an instruction manual!” Point taken.

Unfortunately, this whole “customer dialog” thing isn’t easy. I could submit a metadata update to the game’s description to let people know that an update is coming, but on Windows Phone Marketplace that requires its own cert pass, which would block me from actually submitting the update for several days. Ultimately, I decided to just release the update as expediently as possible. On Friday evening and much of Saturday, I created a simple instruction screen with version notes and some core gameplay tips:

By Sunday, I was squeezing in stability improvements and improved error reporting (to help track down some of the more elusive bugs that have been reported) and submitting to cert. I’d like to include a more interactive tutorial at some point, but for right now, the priority was on helping our customers have a better “first play” experience.

I’m so grateful for everyone who’s playing Rare Earth – even the people who don’t like it (yet). I appreciate your passion, and I hope you stick with it for this update (and beyond)!


Conventional wisdom is that only the most polished and complete games are successful on mobile phones, but some guys made a rudimentary implementation of Pictionary and sold their company for $200 million, so screw conventional wisdom. I’m going to try something different.

In a few days, Rumor Games will be releasing Rare Earth on Windows Phone. It’s a project I’ve been working on for a long time (in mobile game terms). It started as a prototype to see what kind of fun ideas would come from playing with orbital mechanics. Over the last few months, it has grown and changed, leading to several spin-off experiments. But the core mechanic of flinging planets into orbit was something I wanted to see through, and while the experiments were fun, none really brought it to the next level of excitement that I was looking for. Usually, a prototype like this would end up shelved and never see the light of day.

Now, I’ve followed other peoples’ projects that seemed interesting and fun from the outside, but ended up being canceled for one reason or another. Maybe the sales projections weren’t quite where they needed to be, or maybe the product just wasn’t gelling right. But my interest was real and genuine, and I absolutely would have tried them, and would have supported them if I saw promise in what I tried. And with the low barrier to entry of mobile, why not let people try?

All of this led me to this experiment. I’m going to release Rare Earth as-is – beautiful, but unfinished. There are no tutorials, no music. But there is an opportunity. I’ve included a (to my knowledge) one-of-a-kind voting feature, to empower players to help direct future updates. I hope people will see as much promise in this game as I do, and I want to hear from them about what excites them the most.

I want to start a conversation. Email us. Tweet us. Write reviews for the game. I promise I’m listening, and I promise I’ll keep working on Rare Earth as long as there is interest. In the meantime, we’ll keep working on our Next Big Thing.

Great Artists

Good artists copy, great artists steal.

– Steve Jobs, by way of Picasso (maybe)

Steve Jobs famously appropriated this quote, and it’s been used, out of context, to justify all manner of evils ever since. It has been twisted to mean, “Do what it takes to be successful, because history remembers the winners, not the innovators.” Watch this video of that famous line again, though:

Steve Jobs (and Picasso) are not actually telling people it is okay to outright steal. They’re reminding us to learn from the best. Build off their successes. Improve. Iterate. Not claim someone else’s inventions as our own, but use our limited resources to deliver new value instead of reinventing the wheel.

I’m going to take a page from his book and steal his quote, with my own spin:

Good artists copy, great artists incorporate.

– Kevin Tarchenski