Tower defense games are a dime a dozen, give or take up to $20, so it's always nice to find one with a twist. Therefore, I present to you Comet Crash, a downloadable tower defense game available for the Playstation 3. The developers call it a "tower offense" game, which pretty much captures the twist. In addition to spending resources to build up defenses that stave off waves of attackers, you also invest in your own waves of attackers to take out the guy on the other side of the map sending attackers over to you. It's particularly good for multiplayer games for up to four folks on the same screen.

A new update -- free! -- includes a harder difficulty level (as if!), more multiplayer options, and more places to fight. From the announcement:

* 'Expert' difficulty setting for seasoned Comet Crash players. You'll see a surge in enemy attacks that will put your skills to the test.
* 4 new Resurgence levels-one unlocked at the end of each comet during the Campaign. Resurgence levels may require completely new strategies. Beware...no hints!
* 4 new Battle maps to mix up your games a bit.
* Battle timer setting. After the timer runs out, all mobile units generate at 8x the normal rate which should bring games to an exciting finish!
* Thorium setting to tweak available resources in Battle mode.

Great work, guys! If you're taking requests, for the next update, I vote for the option to play skirmishes against an AI opponent and online play, in that order of preference.