The colliders are already quite a bit smaller than the sprites are but I might need to go even further with that to account for the speed some of the enemies move at. Good point!
And I wasn't sure about how the dying works as well, in the end we decided to keep it this way. But disabling the enemy colliders and only load in the level again once you hit the floor collider would have been great as well :)
Thanks for the feedback, all fair points I'll be taking account of for the next time we create a game :)