Thank you for playing my game! Audio mixing is definitely something I should have put more effort into. There is another enemy that gets introduced, but it isn't until the last level, which is a problem with the game. The second enemy has spikes on his head so you can't jump on him. The only way to beat him is by dashing through him. There are also static spikes and bottomless pits that get introduced. The main incentive for getting long combos is to get a better score. You get ranked at the end of the level based on enemies killed, combos, and time. But you're right that there isn't much of an in game advantage to combos. I guess the spike enemies sort of give you an incentive, but they don't get introduced until the last level. Your suggestion about giving the player health for combos is definitely a good solution that would make the game a lot more fun. Thanks for the useful feedback!