My wife bought this for her dad for father's day... Honestly, it's amazing for a Wii shooter.
I can't really describe it, it's like MW2 meets Big Game hunter meets that weird game where you have to shoot bonuses for insane ammo, score multipliers, etc. You get like 5 rounds of semi-auto rifle and single shot shotgun in a weapon switch situation. Big game you have to kill with rifles, birds have to be killed with shot gun. (That's a huge spoiler by the way, my little fucker brother in law kicked my ass until I figured that out)
Long story short, it ain't Final Fantasy, but goddammit it's fun. If you like Wii games, and like shooters, it'll be worth your while.
I would suggest the full rifle set-up, though. At least some sort of Wii gun set up. I would imagine it's almost unplayable without it. It moves very fucking fast.