I have helped you. I've fixed your platformer engine, made your ground look cooler, and introduced death markers. All you have to do is: 1. Remix this project. 2. Select, Copy, and Paste the ground and the platforms in different combinations in new costumes in the grassy block sprite to create new levels. 3. Select, Copy, and Paste the Spikes and lava blocks in combinations in the costumes of the Death sprite to create new dangers. 4. Share the project + Get a nice title + Credit me!
Kindly develop more levels and contact me if you need help/anything breaks/things are unclear. Just reply to this project. This took me a while, so please appreciate.