A game like this doesn't come around very often, these days.
Ever played Metal Slug, Contra, or Gunstar Heroes? This has the same shooter formula, with graphics you'll likely never see again (in a good, original stand out kind of way). Some people complain that the game is too hard but I didn't really have much trouble, and was quite surprised at the pokes at the difficulty. Either way, these complainers still had mostly positive comments to say about the game, and the few people that picked this up really like it.
The game isn't perfect, as cheap deaths are abundant (impossible to avoid or hard to locate bullets kill you easy when it's 1 hit deaths) and none of the gun power ups that you find through out the game really give you a sense of power.
Besides that, the humor is great and so is the game play. Riding a 60 foot snow yeti while crushing and eating Soviet Russians never gets old, nor does riding on the back of FBI agents before chopping their heads off. There is plenty of replay, and 2-player mode is twice the fun. For $20 new, why not?