The most noteworthy thing (that I'm sure MANY people will notice) are the color scheme. There's a lot that jumps right out at you from the alien guy alone.
This is also a very "busy" piece with a lot of stuff/details going on, from the can of slime fizz with it's contents leaking out to hammer in the fact that it's SLIME fizz soda, along with the crazy straw (no REGULAR straw would do for this guy, hmmm?). To the multi-hue suspenders (is this Mork-esque or a coincidence?).
To the hair (not just multi-hued itself, but with pops stuck on top. What's the story with THAT? Messy eater? Fashion statement?). And that's just the guy himself. The background reminds me of the cool "space wallpaper" background art I'd find during image searches.
Very cool space(y) art!