This is a pretty spectacular visual feast, with a great sound stage. The acting's pretty good overall, and I think the experience is well worth it.
The “original” 1982 movie of Perseus works better for me, in that beating the Medusa is not so random, but I think this retelling is right for the times and doesn't weight too heavily on any one thing. You might find the, “I'm just a man,” commentary a bit wearying towards the end, but it'll be ok: there's big monsters and the right dudes get theirs where it counts.