At the moment I'm working on a new project; to recreate the PS3 Lemmings levels. However, levels involving teleporters has been my biggest struggle so far, especially when multiple lemmings need to go in at once (examples being in Fun 5 "My first teleporter", and particularly Fun 9 "Watch how you go now" where there's a short time limit). In the PS3 version you can get as many lemmings as you want, when you want. NeoLemmix only counts the total frames for one lemming, and then for another etc wasting time. To get multiple lemmings in and out I have to place several invisible teleporters and receivers with their trigger areas next to each other (see attachment below).