Wow!... I actually liked it

Gave no errors for me, everything worked fine, here some suggestions:
- If the player is standing on a cloud, make the player have the same velocity as the cloud, because he moves off else...
- The player is able to get "stuck" in a cloud for a moment... This doesn't look good... but you'd need to do more cracy collision detection else...
- make the camera move with the player a bit more... The problem is, that the camera currently always looks in the opposite direction as the player walks, because of the algorithm. Either make it strictly follow the player, or (better) make it move slightly farther in the direction the player previously walked.
Everything other than that: Awesome work! Just the right size a game has to have for learning game development. Move on with somehow a bit harder game ideas. As I see you even used procedural generation here (the moving of the clouds and the clouds itself), why not go on with a game focused on procedural generation? (believe me, these algorithms are fun!

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Offtopic: @Riven: aren't [ol]'s part of bb-codes?

I'd like to have them...