Your game is fun to play.
I like the mechanic with the jump that gets higher by collecting friends.
The door mechanic with the keys is great and works well.
There is 0 audio. You could have added some music and sounds to it.
An easy to use and free sound tool is SFXR. It creates sounds for things like jump, collect, explosion...
The line in your ground/wall is sometimes cut off. You could have added more tiles to your tileset.