I like the underwater setting. I suggest you should fix the mouse input to up/down only (or assign keys instead) and leave the rest to WASD. (i cant get around the curves with the mouse only, therefore need the WASD anyway and when i slightly move the mouse out of the centre the shark gets off course again which is annoying)
i love these tunnelflying games, but this ship is too hard to control with keyboard. Maybe start with less speed? Needs definitly a hotkey for restart!
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