Am I a man or am I a muppet? If I'm a muppet then I'm a very manly muppet!
BGG says 5-6. The rules here say 5-6. The numbers howing at the online retailers who will carry it show 4-6. Is the new version changed in such a way as to support 4 players, or do they just have the wrong info?
I don't have a definitive answer for you - but I have trouble imagining how the game would work with less than 5 players unless they've made some major changes.