Well I got it yesterday morning and I've been playing it quite a bit. I'm having no problem with the control. In fact, I love the control. I've settled into using the stylus and it seems to suit me really well - there are plenty of custom options too, which is great. It took me maybe half an hour to be truly comfortable with it (and realise I was hitting the bottom right of the touchscreen with my hand) but, when you find your way, it works. The weapons, morphball and anything else you need are very streamlined so there really isn't much to keep track of.
At first the graphics were a little overwhelming in that the textures are quite complex and sort of meld together in the first area of the game. However, a little way in the true beauty of the graphics reveal themselves. It's a lovely looking game. But that's just the graphics.
Sound is superb. Metroid Prime style all the way and really works well.
Single player adventure mode sees you searching for things called Octoliths in different areas. It is far more linear than a tradtional Metroid game, especially early on where you just encounter fairly boring enemies in fairly boring environments. However, as things go on, the more Prime style elements start to return with some great morphball sections and some tricky 'how do I get there?' bits. However the emphasis is on combat - Hunters find you and attack and things get very frantic indeed. Think Quake 3 and you'll know what it's like. A few boss battles (not great) and platforming sections break things up. Overall so far the single player isn't fantastic in the way (I felt) Prime was but is certainly enjoyable and gets much better as you go along.
Multiplayer is what this game is about though. It really is like a handheld Quake 3. Playing online is so easy and I've not had any lag yet. It's streamlined, the environments are great and there is huge potential for differing playing styles. It couldn't be more fun for me in multiplayer. Really great stuff, and I've only tried the basic Battle mode - there are loads of other multiplayer modes to try. I'd say this will keep me going for a long time.
So far, overall, this was worth the wait. It's a handheld Metroid-styled Quake 3 with a decent single player mode thrown in for good measure. There is a layer of polish that really shows where the effort went. Yeah, I'd love a more Prime type single player but this was always designed to be a multiplayer game and it works. Great stuff.