I mean, objectively everything about this is good: clean animation and the like, but I struggle to understand how this is a Metal Gear parody at all.
There's an earlier review that summarizes my thoughts pretty well: Newgrounds these days is so bogged down by its own self-obsession that nobody is trying anything new, and that really hurts this particular film a lot: for a film called Metal Gear Awesome 3, the only gag related to Metal Gear in the whole thing was a post-credits scene!
Every other joke is reliant on the audience being familiar with Newgrounds stuff. I laughed at some of it sure, but I doubt I would get much out of this if I weren't familiar with Tankmen, Alien Hominid, and Madness. Even then, I feel like most of the laughs came from just recognizing things rather than from genuinely finding any of it funny: the only one I remember is the blood splatter forming two guys having butt sex which is admittedly kinda funny, but nothing else springs to mind.
In the end, it's basically a glorified Newgrounds commercial: it doesn't do anything new (or even try for that matter) or interesting with the source material.
It's basically a well-animated parody of a parody, when it had the opportunity to be so much more than that.