Ecco is a very original and hellishly hard game. You control Ecco the dolphin, navigating the waters, saving other trapped dolphins (which of course were left on their own here), finding key diamonds, schools of fish and pockets of air deep down in submarine caves.

Ecco is capable of moving at very high speed but has little in the way of brakes. Turning corners without smashing into walls is tricky to say the least.

This run takes no damage, despite the fact that this was not intended to be possible.

This movie has an Atlas Map encode of Undercaves, which shows the standard encode overlaid on a zoomed out map.