This was much better than I expected it to be. While there's not much to get excited about from the dialogue and more jokes hit than miss, the interplay between characters makes up for this as you believe they are a real friend group in over their heads, even if they do settle into the reality of their situation a bit too quickly (but that's true of many, many movies). Keith from The Office and Brian from Spaced carry most of their scenes and hold everything together, and this is balanced out by two strong performances in the antagonist camp in a crowd of otherwise unforgettable baddies.
There's a few strong moments that are genuinely laugh out loud, and that's more than I expected. Best of all is the sub 90 minutes running length, this film does not outstay its welcome. Had they tried to pad the material out to 2 hours, the film would have suffered.