You have to press the spacebar first and then use your mouse. To change the size of the pen, press keys 1-9. Press flag or X key to erase all. The keys for color: Q= red W= orange E= yellow R= light green T= gark green Y= light blue U= dark blue I= purple O= purple-pink P= red-pink A= black S= white D= grey F-J= skin colors Every color makes a different sound.
This is probably one of the most interactive games I've made. Took me hours to figure out these new blocks. To be fair, it didn't too long, and I'm just exaggerating. Please let me know any bugs, and maybe suggest more colors. update 1: Took my friends suggestion, bugs fixed