Yes, it sounds like a rip-off of From Dusk Till Dawn, but John Gulager's film has a much more interesting backstory that you might believe, or remember. Feast was the film "Project Greenlight" made that made independent filmmaking the hardest thing to watch on television. Ever. That show is now history, and Feast barely escaped with its life. Savvily, the Weinstein Company is screening it as a midnight movie on Friday and Saturday of this weekend before releasing it on DVD in October.
(for some reason the only theatre playing it in town screened it at 10:00pm so I'd check in case it's also not a midnight showing in your neck of the woods)
It's not high art or fine cinema, but it's a surprisingly satisfying horror/monster movie that fully appreciates where it came from, where it's going and still makes you jump in your seat, squirm, and laugh out loud. In contrast to all the derivative crap that's invariably shoveled our way (e.g. Jackass 2), Feast is a fun little horror movie that genre fans will really appreciate. Henry Rollins plays against type brilliantly (as the "poor man's Tony Robins") and he was the main reason I decided to check the movie out in the first place. I didn't go in with high expectations, but it's amazing to see what really creative people can do with a tiny budget. There's no significant CGI (and certainly no CGI critters) and IMO the movie really benefits from the visceral nature of actually having monsters and blood and guts on the set for the actors to interact with. It also leads to the most satisfying horror movie climax in recent memory (it's very much an "it's about time someone did that" kind of thing). That being said, it is a gory movie about people trapped in a bar while being attacked by monsters so don't expect anything ground-breaking, but if you like gore and things of that sort, this is definitely a movie to watch.