Art for my game update, looking for feedback. Thread

I'm working on an update for my android game, Fart Man. I'm doing my best to work on graphics, even though I'm more a programmer and designer than a graphic artist. I'm looking for feedback and advice on how improve my art. Please check out the graphics below and tell me what you think:

Fart Man in green outfit.

Blimp.

Grim Reaper.

Rocket.

Yo do you mind my feedback as a pleb. Im also a programmer who tries his best to work on graphics. but i want to throw my opinion in there!

I like fart man but is that a mustache or teeth?

I think the blimp is looking pretty clean but it makes me uneasy, i think because the shading doesn't follow the shape of the blimp and the black outline of the oval disappears at the intersection of the bottom fin.

The grim reaper is cool but the hood animation bothers me a little.

The rocket is my favorite, i like the design, i think the shading works here (maybe not on the bottom fin) and the fire animation is amazing.

Those are my thoughts keep doing what you do!

Thanks for the feedback, peeps! It's very appreciated and will be put to good use!

This Grim Reaper is so nice!!!

source: PNG