I hoped you'll make an appearance and there you are.

I admit Astroid City should have more ways to continue from a point you already reached. The checkpoints are there and I don't think there should be more but they should be fixed because they're slightly bugged and don't always work. There's also another bug in the turtle shell part where it sometimes happens that the last door simply won't open. I suppose that if the level was bug free it would already be a lot better. But I don't really care about repeating a whole level so much, I'm probably a really patient person. Which doesn't mean I didn't swear badly each time the shell bug took place, a player should be rewarded for doing everything right.

I don't know if I consider this level fun or not. I'd rather say that what kept me interested in it was the sense of achievement it gives. Either way I like the level, it's one of my favorites along with the Fortress of Floods.
I have no idea what this acronym you used stands for but it sure sounds like something that could use some betatesting if you know what I mean.