Well, a one-shot doesn't have a set limit, nor does it necessarily need to be a chapter's length. For example, when I wrote my one-shot Indebted, my average chapter length was about five pages. Indebted weighed in at eleven. Just thought I'd clear that up for ya. Anyway, just as a select few chaptered stories take cliffhanger endings (one of my stories did this, if you didn't count the epilogue making it rather obvious what had happened), one-shots can be cliffhanger endings too... if they're done well, that is. Usually, people get irritated when someone ends on a cliffhanger and doesn't make any attempt to explain themselves, but it really depends on how skilled you are and how much you want to leave to the readers' imagination.