For anyone wondering about Dark Void Zero, I just played it, so here's a bit of info. It ran smoothly on Windows 7 64-bit PC. DVZ has three difficulty settings and three stages. On the easiest setting, it took approximately an hour to beat. On the higher difficulty settings, your enemies take more hits to kill and it seems like it could be fairly challenging. It's basically a 2D exploration game a la Metroid. There's a bit of backtracking, and you can jump, shoot, and use your jetpack (which is sometimes taken away). You're only allowed to carry one weapon at a time, but there are various types. You basically go around levels killing baddies and collecting keycards to unlock doors. At the end of each of the three missions, there's a boss (sadly, it's the same one each time with a palette swap). The story is generic but it fits the faux retro theme. If you don't mind a short game, I'd say it's worth it while on sale.