It needs something
You definetely know how to play guitar and animate. No doubt there. But the storyline is cliche, and not exciting.
Suggestions
Record a song with an entire band, the solo acoustic guitar didn't fit. For this cartoon, a slight synthesized keyboard melody would be better, watch superhero cartoons you'll see what I mean.
Please, create more interesting characters. Why is he called Death Man? There is no distinction between charatcers.
The villian had a bad childhood. You could have used that to make him a very interesting character, but instead made him the flat, boring, stereotypical villian.
The man is smart enough to create a superdrill but confuses it with swamp gas? Please.
Why is the man with the knife helping Dr. Vlatelence? Why can't he talk?
What am I saying, ultimately? The script needed work. A lot of it. Every single cartoon needs to have good animation, background animation, and script. The second two elements are lacking.
To make a really good cartoon? Research cartoons, see why they're good. Especially Adult Swim on Cartoon Network, Spongebob, Family Guy, and others. They have strong scripts, which has contributed to their success. Look at some anime too, why are so few popular while they are hundreds of series? Look at a few plays and other movies and tv shows too, understand why are interesting to watch.
You have potential, friend.