I liked the game idea but it is not much fun to play solo. I tried the two players seperately to get a bit more of the gameplay what kind of worked.
The graphics are nice and the split screen is a nice addition. I love the two different playstyles so the players could switch and replay the game. Noice.
SFX is solid and gives good feedback (except for the last hit you take before end of game)
The movement with the mouse feels a bit awkward because you aim and drive with the mouse wich makes it harder to aim and keeping distance. Maybe arrow keys to move and mouse to aim and shoot would be better.
Fot the other player you have solid platforming with interesting enemys so it does not get boring. I would add a possibility to defeat enemys for example by jumping on top of them.
After all a well done game.