Maybe it would be good to add an auto-start for the next level when you win
Also, around which level did the game start feeling like an idle game for you?
It never felt like an idle game because you need to be constantly clicking the "go to next level" button, but at the same time it heavily penalizes you from playing during levels due to sawblades melting your hp.
So basically:
- You hit "go to next level button"
- Hide your main cursor in the corner
- Wait until AI cursors kill everything
- Upgrade
- Repeat