As far as conveying an underwater theme, this really does a great job of putting me in an underwater-themed arcade game where I am operating an underwater mech or a submarine in a side-scrolling shoot-em-up.
As far as that goes, this piece works. I only won't give it 5 stars because I know nothing about Warframe or the character from it, "Hydroid", thus I don't have enough background to say how accurate the representation of Hydroid and their abilities are. I'll give you the benefit of the doubt.
More info about how I review music here: https://codefreq.newgrounds.com/news/post/1089806