Good job finishing the first segment!
I have mixed feelings about this game.
Some suggestions on what could be improved (in my opinion, feel free to disagree!):
- unify the controls (e.g. use a single button for interactions and in a rhythm game, and remove the mouse completely)
- aim for visual consistency: turn off filtering on all the sprites, use the same character sprite for the same character and different sprites for different characters
- maybe turn off Lumen, as it just makes dark areas noisy, and can be easily replaced by a couple of lights
- I would pick a different music for the rhythm section, more rhythmical, and place the notes more to the rhythm (currently it is easier to play with sound turned off)
Overall it's a cute idea to combine idler with a rhythm game, keep it up!