Use the arrow keys. Down arrow to shrink and space to resume normal size. All 30 levels are completely 100% possible. Really. Ultimate Platformer II : https://scratch.mit.edu/projects/19181067/ My record is 32 deaths. (Bad, right?) If you want, post your score in the comments. If you're really stuck, press 'A' to skip a level.
Credit to this platformer http://scratch.mit.edu/projects/15966081/ for inspiration.