So, game's beatable, i really enjoyed the mechanics of emptying and filling the two ballasts, i'd recommend changing it from mouse to keyboard like Q-A and E-D.
I had some issues with the sub's hitbox, it looks bigger than it, another thing that happened is the ballasts not getting entirely empty after some time, after this point the fisics get a little buggy and the sub would turn abruptly.
Still, loved the game, i'm sure this could be well implemented and commercialized.
:D