Smile, smile, smile, Isaac! Doodle

So I was bored and thought, maybe I'll make another picture...got this idea randomly but wouldn't expect it to turn out that cool ...it was quite challenging, but a lot of fun and I learnd some more stuff, so it was totally worth it for me ;D

The picture may be a little distorted because I took it from a bit of an angle to avoid ma shadow on it xD
As for all of my drawnings I would like you to give me as much feedback as possible..and don't be afraid of saying to many bad things about it, that's the only way how I can improve ^^