Most enemies are just things to avoid (lacking interplay). When I see enemies I don't get exciting to avoid them or take them out. All the mechanics are just move, jump, and run. Not too much to do or play around with considering there are no powerups, the "coins" are clumped and generous, and the enemies are mostly obstacles to avoid.
no checkpoints for long level is annoying.
A last item of KirbyKid's advice on School Rush. I will debate it later. Happy new year.
(last but not least as it took me 1.5 year to address, but I think I can be proud of the result).