Loss of Lemmings: Zero
Make the first Lemming Stack just before the penguin. Two of the others will get past the stacker. Platform the small gap with the first - the second will fall down the hole. Bomb at the extreme right hand end on the same level, to reduce the height of the drop (and make it non-lethal). Let the bomber fall and land stunned (if it's killed, start again!), and make it Platform to the exit. The next Lemming (remember the stacker?) will arrive before the platform is complete - delay it by making it an Archer. Bomb the base of the stack to release the horde.