The last two months I have been making a vertical shoot 'em up for the indie games section on xbox live.  It will have 4 player local support (no networking at all) and will feature many levels, right now it looks like it's going to be around 14 different levels. Players can jump in whenever they want in the game. There is also a levelsystem that will be reset every time you die, and every time you level up your weapons will get upgraded. Here's an early pic from the game as it looks right now. But it will change a lot until it's being released, which by the way will be sometime before the end of the year.