I know you said it was only a demo level, but it needs alot of work if you're going to make a full game of it.
Glitches: You can passthrough objects (like walls and moving platforms)
You can double+ jump through objects if you hit the side of time. Like if you jump to the first platform and miss by hitting the side you'll be alowed to jump again and again while the charecter is in the object.
If you stay on moving objects too long you eventually fall through them.
But still, good try =D
keep em coming
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