I was messing around with the level creator and I found a pretty good way to do this so that it doesn't kill your character and the enemy disappears. First spawn an enemy, then give them Shrink Ray item. Here comes the kinda-sorta complex part. First spawn a bomb.Touch the enemy to activate personality traits and go to Use and then select the bomb. Then put each very close together in the order Bomb, Enemy, You going from left to right. If you did it right, as soon as the level starts the enemy will set off the bomb, shoot you once to shrink you, and then die. You may then proceed to make a level where the character can not use items or vehicles.