Things get even more outlandish later, with Jim encountering a mad scientist underneath EPCOT, and a pandemic called the cat flu, which apparently makes people cough up hairballs. It's key to the climax and very, very stupid, which is unfortunate. Drunk, pervy dad at a Disney park is strong enough as a hook, but the preposterous dive into the unreal at the end jettisons all of it for pointless gross-outs.
If you want a critique of theme parks and how they can make you freak out...to borrow a cliche, "Simpsons did it!" The "Duff beer for me, Duff beer for you" bit alone sums up everything that's good in Escape From Tomorrow in a minute or so, while leaving out the crap (and I mean literal crap - there is a long bathroom scene). Good for Randy Moore for defying authority to make this film; next time, I hope he focuses on story first. Disney's right to just ignore it; I wish I could advise you not to do the same.
Escape from Tomorrow opens in limited theatrical release today.