Ok, I best start reviewing...
Dream Land
-It's small. Try making it a bit bigger.
-It needs powerups.
Saffron City
-There's a texture problem on the right FOF (Part of the bottom has a different texture).
Planet Zebez
-Powerups are too easy to get.
-Lava rises a bit too fast.
Hyrule castle
-It needs powerups.
Congo Jungle
-It's too small.
-It needs powerups.
-It needs more detail, it's very bland.
Turret way (You didn't mention this level)
-You die when you spawn. Fix that ASAP.
General problems
-Change the music (I noticed you put the same music on all your levels that have been released). That music doesn't suite many levels, and it gets annoying, especially when it's in all the levels. Try to use different ones for each level.
Apart from that, It was quite fun to play. Keep practising, and you'll get much better.
6/10