Author, please read this review and respond!
Well, this is your first game. I'm also designing my first game for PC too, and it is also a platformer. Taking advice from other people and fixing my game on it, I'll help you out.
Gameplay: You have made a simple platformer, which is nice. The jumping and moving mechanics work pretty well for somebody who is probably only a teenager developing this. Graphics aren't too good, but nothing can be perfect, right? They aren't an eye sore, but they certainly are too plain to get you a high rating.
There needs to be some sort of acceleration for the game, because it feels to jerky at the moment. Jumping needs to be more responsive when you jump off of cliffs. For the scrolling levels, the camera needs to be zoomed out alot more. I also noticed some glitches with the paddles, what not... The biggest problem is with your level design. Some obstacles are just trial and error, and the difficulty is inconsistent.
Graphics, well... Decent. Glow is kind of nice, I guess. You can hand draw some stuff, maybe some terrain? Anything that works.
Presentation needs work. Obstacles will be unexplained at first and the music doesn't even play during the game. Some effects for the buttons might be nice, they'll get you a higher score, and I noticed you re-used the same levels but just put glow on them, that took off about 2 points for me because the last thing I want to do is play the same level over again.
All I can say is that it is a decent start, and maybe when you get better, we can collaborate. You can check my profile too for "Moovlin PC Demo V2".