Wow, this is really good, I would play it longer if it has more enemies to beat! The only thing I think you could improve is the impossibility to lose a combo. I can play just pressing all the keys ramdomly.
Thanks for the feedback! If we had more time, I'd definitely add more variety to the gameplay.
The button mashing is a bit more complicated to fix though. While I don't want to have people button mash, I also don't want to fail the player the instant they mess up an input. I'll have to think about it some more.