I can't do a full review yet (so judges, don't move this thread yet), but here's some things that I have to say:
There's only two designs in this entire level. Try to add a new design in every transitions.
Level lacks in decoration (Custom BG doesn't count, that's part of design). Try to add some decoration around the level to make it feel complete.
Custom BG is alright, but it gets bland because it doesn't change until about 70%. Try to add/make several custom backgrounds to this level.
Not a fan of the gameplay in the retro part. You basically only go straight. It would be better if the gap's location differed.
Overall, gameplay is OK, but not very exciting. If this were 2* or maybe 3* difficulty then it would be alright, but you can make fun gameplay with 4-5* difficulty.
The difficulty of the ball part looks much harder than the rest of the level. Try to make that part easier (difficulty consistency).
Music sync is alright.
Retro design is similar to Triaxis's retro levels. Retro design is from 1.9.
That's all I have to say for now. Note that this isn't a full review, so this thread shouldn't be moved yet. My opinion is that this should be in "Decent".