My first complted game: sky platformer

this is my first project so please don't expect it to be good it is going to be a crap so please give me tips how I can improve and there are two downloadable files  please do not rename these files and put them in the same directory or folder otherwise the game will crash

controls -

1. left and right arrow keys to move
2. up and down arrow keys to change gravity
3. space bar to jump

enemy- 

spikes - they are small grey spikes

lava -  lava is the red box if you go through them you have to restart the game

to win the game you have to walk in water which is light-blue in color it is at the end of the game if you walk in water  the game will restart