Backroutes are unintended solutions present within a level. These can be trivial, but sometimes they are very complicated. These appear a lot in all the official Lemmings games, especially 3D Lemmings. In custom levels, backroutes are usually found by players quite quickly and therefore, must be fixed by the author.
Compression Method 1: Because of corrosion of steel, it's possible to avoid the compressors altogether.
Tribute to M.C.Escher: Because of corrosion of steel, it's possible to bash against the arrows.
Mind the step.....: Because of corrosion of steel, it's possible to avoid the obstacles below.
Backrouted levels in Oh No! More LemmingsEdit
KEEP ON TRUCKING: If the rest of the first ten Crazy-rated levels are any indication, you're supposed to use all the blockers and just barely make it. Instead, if you build the right way, you can bash the crystals and get directly to the exit with more than enough.
Ice Station Lemming: Because of the scenery, success is possible without using the top half to save the bottom.