Simply Incredible; two player is a blast. Bosses can be difficult. Game is fun to explore; different galaxies mix it up!
The controls to this game make it fun, the scenery, the different galaxies that work similarly to each other but different enough to feel like something new.
2 player is great fun, indispensable, because they can lock down enemies, bullets, collect stars and interact with the environment that a single player can't, even if they aim the Wiimote.
It's a game for me, a 31 year old gamer (as of 2007) who's been at it since the Atari 2600 and IBM XT, it's a game for my 8yo daughter (my 10yo daughter prefers being my second player) and my 5yo daughter (she's my 8yo daughter's 2nd player)...
I've never seen a game work for such a wide age group.
There's really not much to add to the 234+ reviews for this game - it really is that good. Go get it.