I saw the original video release, not the more recent EI Cinema re-release "Collector's Edition" which cut some scenes that ran too long without adding anything (so I've read). It's true there are some scenes that don't contribute anything: people walking up flights of stairs when we've already learned the building's layout, and the like.
Before the movie started, there was a trailer for Rock and the Money-Hungry Party Girls (1988), which looks pretty awful! Looking on the IMDb at Camp Video's titles, they have a lot of low-budget stuff that doesn't seem to have been widely seen of late. Let's see these put back in print!
Slime City is actually pretty enjoyable in a low-budget gory horror kind of way. Another user mentioned Body Melt and Basket Case, and those are fair comparisons I think, although Frank Henenlotter's Brain Damage might be more accurate than his Basket Case, though without the far-out visuals. Cronenberg may even have been an influence on this director.
A guy and his girlfriend check out a new apartment for him, which his friend helps him move into. His friend affectionately calls him a "slime" for wanting an apartment where maybe he can hook up with women other than his girlfriend, who is a "good girl" or possibly frigid.
Initially it seems the apartment building is full of retirees, but he meets a sexy punk club- goer, and a gloomy garbage-picking poet. The poet serves him some green "Himalayan yogurt" and green alcohol that belonged to the late father of one of the tenants. The poet has blue yogurt, since it's "his color." It looks pretty awful, but tastes pretty good.
After having the meal, and hooking up with the punk girl, the next morning he wakes up covered in clear slime. Later, his skin erupts into a mottled mess, dripping all over, and he's only recognizable because of his clothing. He kills a bum, and is restored to normal.
It turns out that the late old man was an alchemist of some kind, who committed suicide in the basement with his followers, and there is now a collection of colored "yogurts" and wine bottles and books in the basement. Alex is addicted to eating and drinking the stuff, and can't keep anything else down. The movie gets ickier and gooier as it goes on. Recommended to fans of that kind of thing.