It's true, there are a lot of bugs in the game and I fully expect a hot fix within a week or two to address some of them. The game pauses or freezes during some load screens or just fails to load opposition in certain levels. Some of this can be addressed by installing the game to your machine and clearing your system cache of any errors but still, it's annoying.
The gameplay is hampered by all of the game not being readily available to you. IMO, you should be able to play the game, get the next level and maybe unlock an alternate way to play the first levelafterwards, not have main level stages require gold and silver cup scores to open them. It gets tiresome playing the same exact levels, even if your doing them in Untouchable mode, or Friendly, or Speed runs.
That being said it's still an immensely fun game filled with satisfying ways to kill bears, and while it's not a great game, it's no Superman either. A rating of 2-3 seems too harsh, I think it's more solidly a 5 if anything.