Here is a really generic platformer using the arrow keys to move and jump. Complete each level by reaching the right side of the screen. Death count and time taken to complete is taken into account for your final score, and the timer starts as soon as you press the green flag. Score is calculated like this: ceil(1/time * 100 - deaths). Full screen recommended. All levels are possible and there is one strange glitch that rarely happens but you may get stuck to the ceiling. I don't know why please tell me so I can fix it.
All of this code is original and I did not copy it from anybody else. Feel free to remix and add more levels. To add a level, just add another costume to level, traps and boosts, even if you don't put anything in the costume.