As far as games go, this isn't the best, but since Open Season is a movie game, that alone just makes it worse...
The game does admittedly look fairly good. One would expect it to have rough edges and crappy visuals, but it does look quite good, almost movie like. The audio is also above average for a movie game. The bad thing is, this is one based on a film, and the dialogue usually spoils the film's jokes by telling them in game. This is no exception.
In terms of gameplay, its a no-brainer. Sneak up to a hunter, roar and repeat. Throwing certain animals makes for mild amusement and throwing the deer at shields is useful, but apart from that, thats it. There are mini-games involving rolling down a mountain in a snowball, or shooting porcupines out of a bra-catapult at hunters. While the varied gameplay is kind of nice, there is one problem...
Everything is just too easy. My brother rented this game purely for the gamerscore, and asked me to play it, after saying it was kinda boring. 5 hours later, I obtained all 1000 Gamerscore, with only minor difficulty on the snowballing route getting maximum "wild points" possible. It went back today. There goes one day's worth of 1000 GS...
So in closing, if you're a "Gamerscore whore", then this is a really easy 1000 points. If you're actually looking for a game to play, then look elsewhere...