The offscreen is party because i had to shrink the screen in 800x600 for zoom issues, but forgot to resize the canvas (ops!) but then I choose to keep it because it add a little bit of difficulty to the game, especially in the level with 2 enemies.
The green character... I suppose it's a bug related to the crt fiter, it's supposed to be much lighter green than the others, but somehow it's not. Will check after the voting period. Thanks for the complete feedback.