The platforming is excellent though my only caveat is the color choice. I`m really straining my eyes looking at all the bright red and yellow lava.
Reviews for "Fathom"
This game sucks!
The music sucks!
It's too fucking difficult!
Why is this on front page anyway?
Another great concept wasted due to unfair difficulty. A friendly advice: There are reason for the existence of difficulty settings.
really terrible music. abrasive.
It's every other "hardcore retro" platformer on NG, except a bit worse.
First off, the music. It's a ten second loop that plays throughout the game. It gets grating really fast, to the point I'd probably rather hear the Hydlide theme for an hour. There is a mute, but it's one of those "both music and sfx" things, which is really dated by now; we've had games from 2009 that can give you a choice there, and that was eight years ago.
The graphics are honestly either generic, or annoyingly cliche by this point, depending on your POV; for me, it's the latter. I have seen this style multiple times throughout NG as of late, where the character could likely be made with MS Paint by someone who has no pixel art experience. I don't think that "more bits are better" inherently (I prefer non-"pixel" stuff, but I would prefer that they put effort into them so they look good), but I swear, I've seen that design so many times, it wears on me. The best looking things are the spikes, and the worst is the background (which I describe as "using the square tool on the entire canvas for black, then putting some dark squares on it").
Gameplay is meh too. There's nothing really hardcore about this, to be honest. Sure, I die a lot, but that's because I die in one hit, and it doesn't really matter because I'll never get a game over, so there's no real stakes to this aside from "time" and "score", but those don't really affect anything. The level design is rather generic, the most original thing being those gates, which were still likely inspired by something. I mean, here's some spikes, some disappearing/death blocks, and so on.
The gliding gimmick, to be honest, is rather boring as well. While almost every level requires it to win, if I were to remove gliding, the game would play the same with the exception of being unwinnable. Gliding has been done right before, like having updrafts for more air, or running to gain momentum. Speaking of momentum, another reason it fell short for me was how slow it felt. It felt like the air was molasses or something.
Overall, I realize you're a new author here, this being your second game, so please, don't take this personally, as I would tell anyone this. I think you should improve on this. It's clearly retro inspired, and there are retro games that have done this better; go play Super Mario World some time, which had a really good gliding mechanic with the cape.