I rememeber your progress from dunno how many months ago, I'm glad you sticked with this game.
Gameplay is great so far, but your design is lacking. My suggestion is to experiment with level design and see what you like to make, and what ppl like more to play. Spark 3 can be of inspiration (ofc you already know it); but also more sandboxy experiences ala mario 64/odyssey with missions. I could also suggest a pure corridor A-B where the only objective is to reach the end flag.
PS: since this game seems a pg-8 you should avoid your Main to "flip off" in the cover. Rebellion per se dosen't need to be vulgar (see jet set radio).