Got my tablet+ a little challenge

I got my graphic tablet on 23.07.16 and I did the lineart for this with it, using SAI. I decided to give myself a challenge and here is the result. I used only the 5 colours you see in the background. They are pretty bright, as you can see. I'm gonna do a normal version of this drawing (using whatever colours i want to) and upload it, but i don't know when. Again, I'd like constructive critisism. Thank you and please check out my profile for my other few (only 2 more ;-; ) drawings. I don't think I'd get noticed soon, since my art isn't as great as other people's that have a lot more experience with drawing. If anyone views my art, please leave a comment even if you don't like it so that I know that someone actually saw it ;-; let me know you've noticed me, senpai ;-;