Helmet Game.
Platformer with lots of tools and weapon to get around. The ability to add "Diagnostics" to the screen, such as health, ammo, location in the world, proximity, gps, atmosphere gauge, etc.
Cool box within a box physic. Where you can store stuff in a "void inventory" which is a box following you around. With more void inventorys you can store them inside each other. Is there a void world somewhere, or are you inside one already.