Here is a total walkthrough (All done by me Alien) of Run3_r: Run3_r walkthrough. The text goes fast so you have to read faster. (The reason i do not die straight away after my invincibility wares out on one of the videos is because i have god mode on. Also at the end the scorebored show my points going up.)

A nice tip on the forum posted by skateboard: "After you turn the wheel under the acid, the suits on the opposite side of the room are accessible. They last long enough to let you break through the floor in the acid tunnels and reach the ladder without dying".