In The Abyss, the planet Nonterraqueous is controlled by a master computer. You control a robot seeker drone trying to find and destroy this machine. You start with a laser and can get bombs but at swap stations you can change form. This new form cannot drop bombs or shoot lasers but it is not harmed by acid drops. You also have psyche stations that can reload you psyche but be careful. If you overload it you will be destroyed. You don't HAVE to change form for the acid drops. If you're quick and lucky enough, you can just avoid them. If you touch a proton thruster, an acid drop touches you in your acid vulnerable form, you overload you psyche, your psyche goes to zero or you're too low when you drop a bomb, you die.