Very polished game, and fun to play! :D 

Great as always and lots of fun, the two game modes are a great add. More "slingshot" potential would be cool, although I imagine that would be pretty hard to balance with the physics. Maybe a thruster mechanic to briefly increase the linear velocity would do the trick.

This is definitely a top-tier game jam game. You even put in multiplayer?!?! Only gripe is that there's no sounds or music, but I think adding them would definitely make this the most solid game in the jam.