Decent, needs improvement, though
This is a decent game, no doubt about that, but there are some things which you need to improve upon.
1) First and foremost, you need a key mechanic that defines your game. This game, while good, is just like any other platformer. You need to think of some fun gameplay change that makes this stand out from the rest. The game design is the most important thing in any game.
2) Secondly, important, but not so much as gameplay, is the presentation. I'm not sure about your art skill, but the graphics seem a bit below par. For Lil' Blue, for example, he looks kind of sketchy where you could've used the circle and line tools to give him a crisp, solid look. Also as part of the whole presentation, you need to have some sort of background music. So far, the only sound you have are the SFX when walking and getting a coin.
3) These are just little tidbits, but be sure to include some sort of plot to keep the gamer interested, perhaps include options like customizable controls, etc. Little things that can make your game even better.
In closing, it is a decent game that needs work.