When the burning crate falls down the stairs, with Rick still in it, how heavily it is burning completely changes between shots.
In the "Vomit" scene, the door leading to the young married couple's room is covered in green slime but in the next shot it is clean.
When Richie is running down the stairs, there's no vomit on left hand, but when he asks for a handshake from the policeman there is now vomit on his hand.
When Richie gets the pencil shot into his rear, he knocks over the table (which two guests are also sitting at), knocking over all the items on the table. Then Richie and Eddie fight in the kitchen, and it then cuts back to a reaction shot of the two guests sitting at the same table, only now the items on the table are all suddenly back upright and intact again.
When Gino breaks the front door window the entire pane falls out but in later shots the pane of glass is still in the window, albeit still broken, but not as before.
There is absolutely no reason why all the guests should go into the corridor to vomit.
Despite eating only one fish each, all the guests seem to vomit gallons of radioactive waste.
When Richard pierces himself with his Hotel Manager badge, lots of blood comes out. We then see Eddy on his bike and then go back to Richard with no blood. This is not a goof as it is obvious that Richie has put a fresh shirt on for another try at putting the badge on, you just don't see him change it, instead of seeing him change his shirt you see Eddie on his bike.
Around the time Eddie can be heard to say, "No! No! Not the fridge!" string is visible pulling the lamp that is knocked sideways.
Reflected in Eddies glasses several times through out the film.
Shadow cast on the banister as Richie, Gina and Eddie escape the sick ball.
Despite never meeting Gino before, all the guests decide to vomit on him at high velocity, that it causes him to fly out of the window and landing in the sea to drown. Which means that a group of innocent people just killed somebody for no good reason.