Hey all,
I dont have any information for the 2-player tutorials, however I do have information on the ported systems for lemmings. I found this interesting piece of information from Wikipedia Encyclopedia (which is my main source of information on the net right now for most things):
Two-player mode
The original Amiga Lemmings also had 20 two-player levels. This took advantage of the Amiga's ability to handle two mice simultaneously. Each player would be presented with their own view of the map (vertical split screen), could only control his own lemmings (green or blue), and had their own base. The goal was to save more lemmings (color irrelevant) than the other player. Gameplay would cycle through the 20 levels until neither player got any lemmings home.
Two-player levels were also present in the Sega Mega Drive version, along with some levels unique to that version by Sunsoft, the company that worked on it. They were also present in the Super NES version.
Hope this helps.
Tim.