The graphics look great, and the music sounds great! The controls are a bit wonky at times though, sometimes it felt like I was hitting invisible walls. I can't say I liked the gameplay though. I'd have liked it if the submarine was fun to control, but right now it's very stiff.
Played twice, but didn't manage to find all of the ruins.

I enjoyed it. The sub was well constructed and looked good and i like the greyish background

Really fun and overall nice experience!

The graphical effects were really nice, and the submarine model was very cool. I was a little confused by the slider on the left, because i at first thought it was the timer before you lost, but then you could also just drag it around. The ability to look around would also have been nice.

agree with the other comment, it looks and sounds great and i like the concept, just feel it's a little slow right now, would be great to see an expanded version

I enjoyed my time playing it. The submarine looks so great, I can spend hours just admiring the view. I think the mood could benefit from a bit more "exploring" music, but overall it's fine. Maybe you can add some kind of locator to make it easier to find the ruins. Also as mentioned before, it would be great to be able to rotate the camera.

Found four of the five ruins and I have no clue were the fifth one is or if I missed one of the others. The basic idea of the game is cool, I like driving that submarine through the depth to find remains of an old civilisation. The art direction has it's own charm, I like that ruins dimly appear when you reach a ruin.

The gameplay was a bit disappointing to me as finding those ruins had no effect on me as a player or the world I've played in. Some effect, may even something small like a fish swarm that of ruins when getting close could've helped.

nice visual (⌐■‿■)

I really like the distinct artstyle/visuals. And though the gameplay is not exactly my cup of tea, i still tried several times to find all ruins. So good work overall!

This is such an awesome game. Can't believe it hasn't got more reviews. The graphics of the submarine are superb. I felt a bit disorientated the first two tries and it's difficult to see. Didn't realize the dark parts were rocks and I got stuck (and unstuck again). Managed to find 4 ruins, but time was not on my side for the last ruin. Good music too and the tings when you got to the ruins also at least showed that you were on the right track. Excellent game. Will play again.

Minor typo on your menu: "lurking ir should be lurking in"
I would also suggest changing your font colour - red on a dark background is very difficult to read. Try white perhaps.