All upgrades are free.
Dive down deep into the ocean sea! Search for gold, find new sea creatures and destroy any that are a treat to you by having your submarine's radar to be as close as you can to the enemy! Dive down as far as you can till your fuel runs out, when it does you can spend the gold you gathered at the shop right after each round! increase the amount of fuel to stay longer underwater, have your missiles do more damage, a wider range for shooting your missiles and much more!
Look around by aim your MOUSE and move by holding your LEFT MOUSE CLICK. Lets see how far down you can go!