Wow. I studied Beowulf in college and my professor made the point that it was the "action film of its day". We had Schwarzenegger movies, they had Beowulf.
Neil Gaiman certainly captured that in the
film version. It is non-stop action. The animation is amazing, with the same technique used for
The Polar Express (2004) with Tom Hanks.
Most importantly, it is the FIRST time a 3D movie looked good to my eyes. My eyes are a bit weird and usually can't merge the two halfs of the stereoscopic views. There was a very minimal amount of “oh look we’re in 3d so here’s a gratuitous trick” except possibly in the opening credits. (I once read that 3D movies often use the first 10 minutes to help people’s eyes “warm up” to the technology so you should always except 3D movies to have an intro like that. In this case it was some 3D coming attractions.)
My recommendation: See it. See it in 3D if you possibly can ($2 extra at the theater I went to)
Tip: When they hand you your glasses immediately check if they are clean. If not, hand them back to the person and get a new pair. Mine looked like my personal glasses after a week of not washing them. I could see better once I cleaned them.