I've played for a couple of hours now (on easy mode .. .. .. don't laugh!) so
my initial reactions to the game are thus:
You are part of a research team stranded on an alien planet when your ship crash lands and your first task is to make your way to a known base. Using the nunchuk to move and the wiimote to point and shoot you make your way through the dingy caverns, punctuated by the bright green of alien slime. From the outset you have a choice of weapons including a rocket launcher which can be selected by each direction on the d-pad so pick your favourite and off you go. The map in the top left of the screen lets you see where the next group of bugs are so you can decide your route from what you haven't already killed. Complete the mission and you then can progress to the next group of missions. Fairly early into the game you can ride a vehicle and inflict twin cannon destruction on the enemy.
I should probably say at this point that I've enjoyed playing the game so far and for £7 it seems like relatively good value to me.
I'm going to focus on the negatives for the next part of this mini review, only because I have very little in the way of FPS to compare it with. I have no real idea of the standards that have been set in this genre apart from a 2 week flirtation with MOHH2 (before the frustration of not being able to reliably connect online boiled over).
1. The scenery isn't hugely detailed, is fairly repetitive and the colour palette is limited. This may just be setting the scene for the alien environment or lack of memory to be able to add more detail. It hasn't detracted from my enjoyment though.
2. There are a limited number of enemy types. Each type behaves, as you would expect from a bug, in a pre-defined manner with little deviation. The difficulty comes from the weight of numbers of these things that can, at times, come at you from all angles.
3. Map layout. One level in particular has had my screaming in rage as I can't find the way to get through to the part where I need to be. I've tried going quickly, slowly, searching every possible route but I can't find how to get to the centre of the level (where I need to be). I might be missing something .. .. .. .. on other levels the path you need to take may as well have flashing arrows pointing the route. This might just be my inexperience shining through.
The positives then?
1.If you liked the movie Starship Troopers and wanted, like every Citizen should, to fight the menace of the bugs then this game allows you to do that!
2.The basic controls are smooth and accurate.
3.There are some nice touches included too. If you get too close to a bug when you shoot it you will get splattered with green goo which needs to be wiped off by swiping the nunchuk. Look up and you can see a dark sky with a beautiful starfield.
4. There are a mix of level objectives including 'reach this point' and 'defend this point' so there is some variety of challenge.
Overall .. .. .. .. so far .. .. .. .. I'm still not a convert to FPS but I will be playing this some more.
A Later Thought: I've just tried out the online ranking game .. .. .. .. up to 4 players co-op against the bugs in a kill as much as you can frenzy. I'm still not good (but I'm better than the person I was paired with

) and already up to 105 in the world rankings .. .. .. .. I realise that will drop once the better players get into this.
It can take a while to match players for these games. The timer starts at 300 seconds and counts down as the players are found (for the free play) all the while playing very martial music to get you in the mood.
I might have to out on a limb and say this is a must have game.
Any questions?