Very good!
I like it enough to login and review. Attention some game mechanics spoilers ahead.
On to review - cool concept. I like the difficulty curve. Contrary to popular belief fuel is very well balanced with depth. It has just the needed difficulty to make it interesting, but by any means its not a diff. game. That being said people seem to have forgotten what dificulty is at all and complain about nuffin.
I find it verry funny how the cargo upgrades past the first level actually make the game significantly more challanging (assuming you are striving for a full load every surfacing) and so for an efficient playthrough they are irrelevant. I am probably wrong, but I dont thinks its possible to make a depth dive, fill 40 slot cargo hold and surface. So essentially this upgrade I find it ... cheeky? ... and well i love it.
As for the difference between ores - to me it was quite obvious whats more valueable, past the 20 and 10 ores - which should have been more distinctive. In the deep there were some wacky ones like the ore which i can only describe as a magnifying glass, but no issue there.
Graphics are solid. Liked the chiptune. I loved everything in game.That being said the main menu needs some improovement. The level of abstraction in the background between the drillbit and the body of the machine doesnt work for me. The drill looks more like a ...lamp? ... of sorts.... and the body of the machine is sorta just lines. I only found out its a machine after i played the game. Maybe you wanted to look as if it is in dark mineshaft or smtg, but i dunno - it didnt work for me.
Overall its a very short game, but it was well done and its very promising.
WE WILL WATCH YOUR CAREER WITH GREAT INTEREST