looking good bro. I have some suggestions however.
1. Try to fix that super spinning attack to have more frames it doesn't really look like its spinning right now just a couple of frames
2. change his soundwave projectile to a burp of gas? I think it would fit better.
3. for assists you might consider Wile Coyote there was a sega game that has alot of sprites you could use for it.
4. also, a move idea for a super maybe. Marvin comes in zaps taz with a gun making him grow HUGE like in the sega game these sprites are from the escape to mars game. With marvin saying oh dear as he runs off.
just some ideas hope they help.