Link to game:  http://staticvoidgames.com/games/WeatherFactoryMeltdown

Here's where I describe my tentative plans for what features to add to the Weather Factory Meltdown game engine and editor:

1)  Custom playable characters
2)  Multi-layered backgrounds (adds a sense of depth to the game)
3)  Inventory System
4)  Editor lets you make your own enemies, bosses, and NPCs
5)  Dialog and Quest System
6)  Scripted Custscenes
7)  Minigames

If there's one thing I'd change in all that, it's probably minigames...I might combine those with an earlier part, so there can be more debugging and programmer collaboration later...

Of course, all this assumes people actually want to collaborate...!