The main mode of play is mission mode, which is exactly what it sounds like. You roll through levels, destroy everything, fight a boss, and then have a chance to purchase upgrades at the end of every level. Survival mode pits you against a never ending stream of enemies as you slowly build up your arsenal and try to survive. Boss Blitz, finally, lets you throw down against a series of bosses (this mode is unavailable in the trial version). We've only had our hands on the trial version (still waitin' on that pay check), but we imagine that these modes will only be made better by the inclusion of Live multiplayer. 2 players can go through mission mode, and up to 4 can play survival. If you've got friends, especially those who may not play tons of games, Heavy Weapon will make a perfect game that almost anyone can enjoy without having to worry about controls or the complexity of making the perfect head shot.
Whether or not you can stomach a ten dollar purchase (800 points) for the full version really depends on your taste (as it usually does). Given the game has 19 levels all playable in co-op and the 4 player survival mode, Heavy Weapon is hard not to recommend. It becomes even easier to recommend when you know that the PC version, which doesn't include multiplayer support or the Boss Blitz mode, costs twice as much. So long as it doesn't suffer from the multiplayer issues that plague Assault Heroes, Heavy Weapon comes highly recommended to action fans and those looking to blow off a little steam in between rounds of Gears of War.