Mads K. Baekkevold’s review published on Letterboxd:
This could have been great, but was ultimately let down by the lackluster execution of some nifty ideas.
For one, Adam Green really should have gotten someone else to play his character. (Which would've made his camera man's "maybe we should just get an actor to play you" a nice little meta-joke.) Not only is he an absolutely horrendous actor (as are everyone in this movie who are playing themselves), but he is also extremely unlikeable - a Troy Duffy-esque frat boy douchebag.
Secondly, don't spend 90% on the runtime on the whole "is this real?"-mystery. We saw a goddamn goblin 15 minutes in, we know it's real, now do something interesting with your idea. Really stretching to fill 80 minutes here.
Thirdly, the self-promotion. Jesus Christ guys, this is tacky. Everyone in the movie wears brand-new t-shirts and baseball caps with Green projects emblazoned on them. Gross.
Lastly...this is just Nightbreed, guys. C'mon.
PS: Be sure to check out the movie's IMDB trivia page. The self-promotion extends further than the movie, and it's clearly written by Green himself: enjoy such tidbits of trivia as "a lot of people thought the movie wasn't great, but then Adam explained it to them and they loved it!" and "people think the movie is improvised, but it's really just amazing writing and acting!" Again: gross.