I think most the hate comes from the game not being complete. It’s a fun game, smooth, free, no ads. It only goes to level 24 at the moment. I think the Developer put an enormous energy wait time and high energy requirements (5 per round for first few, up to 10, then 100 for level 23) because the game isn’t finished. Level 24 requires 1000 energy but you can only have 100.
Solid game from a small dev. I appreciate it.