Undertow (X360) is the first release from Chair Entertainment, an independent developer founded by several Advent Rising (PC, Xbox) veterans from GlyphX. The company, which is also working on the multi-medium Empire project with Orson Scott Card, began working on the Unreal Engine 3-powered Xbox Live Arcade underwater shooter as an experiment, just to see what Xbox Live Arcade was all about.

Needless to say, Chair was pleasantly surprised with the results, to the point where the company hopes to always have a few staff members working on a downloadable game.

To learn more about the game, and the twisted mind that came up with the concept when he was only ten years old, I spoke with creative director Donald Mustard about the making of Undertow, just what's happening with the Advent Rising franchise, and the perils of marrying your publicist.

Shack: The idea for Undertow came from doodles you did as a kid, right?

Donald Mustard: Yeah, it did. We were sitting around and we found that we had a window in our schedule that we wanted--We'd been kinda watching Xbox Live Arcade for a while, and we had some ideas we thought we could do in that space, and Undertow was one of them.

Undertow was an idea that I've always loved, it came out when I was ten years old. For a social studies project, instead of writing a report on the pilgrims or something, I convinced my teacher to let me draw this massive underwater battle that related to social studies in the sense that it was this big underwater culture. I spent a good deal of time as a child just drawing all these massive underwater battles and I thought it would be a really cool idea for a game.

When we sat down and talked about it as a team, we took those arguably crappy childhood drawings--

Shack: I think they're charming.

Donald Mustard: (laughter)--those charming childhood drawings and took that as a core nugget of an idea. As a team, we were able to turn it into something that we think was pretty special and pretty cool. I think what was so cool about it, and what's so cool about Live Arcade, is it gives you the opportunity to really make a more pure, fun game experience. Whereas when we're making a full console title, you really have to justify the $60 expense to the consumer. So you're putting in all sorts of content that, sometimes, might dilute the core essence of what the game is.

Undertow is one of those games that we thought was just perfect for Live Arcade and would allow us to distill something to its core essence of fun and fast gameplay, but still have a lot of depth there. And that kind of all sprang from those little drawings of guys getting their heads shot off and sharks swallowing grenades.

Shack: It's a cool story, because frankly, everyone made doodles like that as a kid.

Donald Mustard: Exactly, and that's kind of the idea. We often do that as a team. When we're sitting around talking about what the next thing we want to do is, we really do look back to our childhoods and all those doodles and those scribbles. I think that there's a lot of genius there, a lot of stuff that all of us thought, as little kids, was really cool. I'm always trying to look back to when I was more innocent and more pure to find really cool stuff that we think would appeal to people now. We do that a lot.

Shack: How does the game control? Is it similar to Geometry Wars?

Donald Mustard: Undertow controls very similar to a Geometry Wars or a Robotron, at least in its most simplified state. The movement of the guy swimming around is controlled with the left stick, and the shooting, at least your primary fire, is with the right stick. Then it gets a little more in-depth from there. The right trigger is a dash, and that really is the secret to Undertow. As you're moving around your guy, pumping that dash button really lets you jet around quickly and dodge missiles and bullets and things like that. Then your left trigger is a depth charge, and you start out with three of them and you can get different depth charge pickups in the map. It sinks and you can use the physics to set up cool stuff. The face buttons are where you are able to upgrade your unit, and do some of the other stuff like that.

We really wanted to keep the controls very very simple. We think that it's a good blend of simple gameplay with a lot of deep strategy that comes forth as you play it more.

Shack: Wait, unit upgrades?

Donald Mustard: Each race has four different units. You can basically select to be any of those four units at any time. And the different units are, basically they range from a small, lightly armored, fast infantry unit to a very heavily armored slow and powerful tank class. Each of those units begins at level 1, and can be upgraded three times

Shack: Can you describe the single-player campaign? Is it just an endless wave of enemies, or are there actual stages?

Donald Mustard: The single-player campaign is a full campaign. The basic premise of Undertow is that this aquatic alien race invades Earth and melts the polar ice caps. It plunges the entire Earth underwater. You play as a human for a while, then as the story kinda builds up you begin to play as the Nemodians, and then you begin to play as the Atlanitans.

Some of the maps are similar to the multiplayer maps, in that they're more Conquest style, where you're taking over bases and things like that. Some of the maps are a little more linear, in that you're sneaking into stuff and some of the maps have big huge boss fights.

The other cool thing in the single-player is you can play by yourself or you can play through with co-op, full online co-op with two people or split-screen co-op, either way you want to do it. It's pretty cool. Just because a game has to be 50MB and $10 doesn't mean we can't give you lots and lots of features.

Shack: As for multiplayer, you're supporting up to 16 players online?

Donald Mustard: Early on, Microsoft was like, "Are you guys sure that you want to do this?" and we're like, "No, no, it's going to be great. We can do it." We really wanted to do 16-player multiplayer. It was just so fun to play it that way.

We decided we were really gonna push it and luckily we started with some really solid underlying code in the Unreal 3 codebase. [Epic] had some pretty good network stuff that they had to work through for Gears of War. We took that and really really really tweaked it, and worked on it for a long time to get the 16-player multiplayer working really well.

If I'm being frank, it was a little more work than we anticipated, but that's one of the lucky things about being independent. We didn't have some publisher saying that we had to ship the game in the third quarter or whatever it was, rushing it out the door. We were really able to take the time, with ourselves and with Microsoft, to really, really test the multiplayer and really find all the little laggy things that were going on and get it really smooth and polished.

Turn the page for more on Undertow's multiplayer, the fate of Advent Rising, and marital strife.