Yes, it's crap. Of course it's crap. It's a collection of action set pieces loosely based on a board game. How could it be anything other than crap?
It's fun though. So long as you ignore 90% of the dialogue and 100% of the largely non-existent characterisation it's quite watchable.
The levels of corniness are spectacular, epic, incredible but they wisely chose to soundtrack the corniest of the corn with an AC/DC tune, masterfully distracting the audience from what would otherwise be a nauseating few minutes.
The experiment itself is pretty well known, popping up all over the place in books, but seeing it reenacted so convincingly is gripping and unsettling. The film sags a bit in the middle but is definitely worth watching.