What's coming next is projectiles. They will come in two sorts: ones that immediately destroy upon hitting an obstacle, and ones that bounce around with either a certain lifetime of bounces or infinite bounces, like a grenade.
I will do collisions for projectiles as an optional feature, so if it's turned on, there would be triggered events for collisions.
I'd certainly like to get more things in, like trampolines, but I'm not sure at this point. This will never be a physics engine, because I'm not going to suffer through rotational dynamics, but things like treadmills, fans, magnets, gravity orbs, and trampolines would be nice. Body collisions will have to be handled in MMF2.