Slumber Party Massacre III's gravest sin is that it lacks what made the first two special. It doesn't even attempt at subverting the conventions of what it is (the first one started as a satire and got trashier in production but stuck to enough of its original intent to be unique) or be really out-there in its badness (the second one, which may be one of the most entertaining rockabilly slasher neo- surrealist movies of 1987). All this is is exactly what you might expect, and yet it only puts in the minimal amount of effort possible in its run- time (ironically the longest of these movies).
Corman sold out with this one - not surprising he would do this of course, but at least this series, all helmed by women, had some teeth and, you know, *ideas* - and either didn't allow the filmmakers to get more creative or never hired anyone good in the first place. Its just a dumb, tired slasher with a final 20 minutes filled with such dumb and *mean* stuff (why do the girls stand by while that one kill happens that could have been stopped in the five real time minute lead up?)
It's only for genre completists, or those who might dig watching what is in effect everything that made Scream necessary, from its "twist" third act reveal (think you know who the killer is? F*** off, like I should care) to the inane conversations the characters have are meant to make them sound like real people and not types; its not really fun enough to be a guilty pleasure or something to put on at a party (like, again, the second one was), and its 350 grand budget feels as cheap as that sounds. Its also not a total crime or offensive (hey, it could be worse - imagine Eli Roth putting his taint all over this), but you could be doing better things with your time.
