If you set your expectations to Popular Culture Historical (as imagined by tv, moveies and pulp fiction) I think you're fine. If you try to be authentic as opposed to mere plausible, you're going to go mad. It'll also be a very tiny game. Further more you should pick both a setting and a time that is familiar.
Classic Greece? Sure, if you're cool with Xena and Hercules being as much of an inspiration as anything you cook up.
Rome? Sure, but we're talking Gladiator here.
Western European Dark Ages? Sure.
Renaissance Italy? Can totally work
Victorian London? Go for it.
American Wild West? Sure.
Constantinople? Eh (and that goes for both Byzantine and Ottoman)
Pre-Columbus Aztecs? Eh.
Mughal India? Eh
Feudal Japan? Eh.
Warring States China? Eh.
The key principle is familiarity, if not with the details then how pop culture has portrayed it. Go off the beaten track and people have to do more and more research, coupled with the fact that the more niche the more dedicated the detail-oriented freaks you've attracted will be. The kind that will hate the bastardization of their favorite era.