I love the idea and look of the game a lot! Same with the tts voice actor, that was a nice touch =)
The songs felt a bit mistimed/not really something you'd want to use for rhythm game music. There's also issues of songs having faster/slower parts, different moments you'd want to focus on for the beats, etc etc, so something a bit more dynamic other than "hit once every 4 beats" probably would've worked better in general. Also, missing a beat is WAY too punishing--most players will only hit once per set of 4, and if it happens to be too early/late they'll take a penalty for missing the 4th note AND hitting the 1st/3rd one.
It's a great start though and I love what you did, I just think it needs a lot more refinement on a core level, especially if this is something you want to keep working on going forwards.