Thanks for the feedback!
The lack of spam prevention was actually an intentional decision. You're supposed to hit the targets right as they reach the attack bar(the sound is different if you time it right) and getting the timing wrong gives fewer points depending on how far off you are. Spamming isn't really a viable strategy for getting a good score, but I probably could have done a better job of communicating that to the player.
The alternative control scheme is something I considered and would have put in the options menu if I'd added one. That not being in the game was just a scope thing.