Resident Evil 4 for the Wii is similar to previous Resident Evil titles, but because of the Wii's controls it utilizes a 3D viewpoint. This makes it easier to play the game compared to previous renditions of the title but it would be impossible to use the Wii's controls in the classic movie viewpoint of the game. The game is a direct port from the PS2 version, meaning it has a few extras from the original Gamecube version. The game also takes a break from the zombie enemies and instead has crazed locals as the new main enemy. One bad thing in the game is that you can buy weapons from a Merchant, which breaks the feeling of immersion. However, upgrading your guns using the Merchant is a must-do if you plan on defeating all bosses.
Aside from this, it's a great game. However, if you've already played the game you should consider buying the cheaper Gamecube version (which still works on the Wii) instead.