This hack becomes pretty interesting starting in late world 3, but also quite hard--at times, unfairly so.
- This enemy drops down out of nowhere and can't be avoided unless you've been seen it before. Try not to put in obstacles which can't be avoided the first time.
- I'm not sure it's always possible to avoid taking damage here, depending on where the Magikoopa spawns.
- This might be too much. I eventually just flew over this level. It's way harder than anything else in world 4.
Difficulty changed from "Normal" to "Hard" because the difficulty is way beyond "Normal." At this rate, the hack will end up being "Very Hard."
Lastly, on a personal note, the bomb excavation sections feel tedious and repetitive because there's a lot of forced waiting. I'd make them shorter.