First of all, if you are looking for the same or a similar expierence as Dead Space on PS3/360 look somewhere else. As a person who considers himself a hardcore gamer but only owns a wii, i have played almost every game on the wii worth playing and i have to tell you this game is awesome, for a wii game.
First this is a wii game. The graphics are not as good as the PS3 so don't expect them to be HD. However this is some of the best realistic (not cartoony or stylized) graphics on the wii, especially faces. They look great and if you play a lot of wii games you would also agree that this is up there with Goldeneye and Metroid Prime 3 with graphics.
Second this is a Rail-Shooter. You do not control movement besides picking certain branching paths. You aim and shoot with the wii remote and reload and switch weapons with the nunchuck. This works suprisingly well for a horror game in that it is more akin to a film and features moments like turning sharply to an alien around the corner.
Third the first level in the game is wierd. It is very confusing and does not represent the rest of the game but (SPOILER ALERT) you play as a crazy guy who thinks people are trying to kill you and starts shooting his felow coworkers. After this scean you are introduced to the actual characters in the game and the story (a pretty good story by the way) is told through multiple characters.
This game is awesome and needs to be played if you love Dead Space, Rail-Shooters, or are just looking for a good wii game you might have overlooked. This game is pretty cinematic and as a bonus includes a visual comic which gives you even more backstory to the Dead Space cannon.
If you liked Dead Space enough to watch that Dead Space anime then you will like this game. If you enjoyed other wii shooters like House of the Dead Overkill or Resident Evil Darkside Chronicles (Which are both great wii rail-shooters) You will also love this game.