So, after a week of trying to get this game, I finally found it at Gamestop. So, here are my impressions of each of the 6 games. I'm going to focus on how each is different from the Wii versions, as I assume most people have at least tried those (and if you haven't, you really should have by now )
TL;DR Short version: The WiiWare games we all know and love, in portable form. Good controls. Modest 3d that helps in Beat.
Interface
On the Touchscreen you have the 6 games with icons the same as there WiiWare versions. Tapping one shows you the controls for the game. Choosing to start the game there is a very short load time then you have the same individual game menus as before, but most of them are in 3D.
Beat
You can either control via the stylus or the circle pad, with the circle pad being a waste of time, unless you have really fine motor control and are able to make micro adjustments. The stylus on the other hand plays very well and is quite responsive. Overall, I like the tilting of the Wii remote better but the stylus does work very well and you won't be dying because the control sucks, unless of course your stupidly using the circle pad.
The 3D works well with the game. It basically gives you 3 layers: The background, paddle and beats, score/status. The differential does make the beats really stand out compare to the Wii version. Of course, it is still fully playable in 2D, as they all are.
Core
Core isn't one of my favorites, but for what it is, it works well and the dpad and buttons work fine. The 3D isn't very noticeable, mostly there for your score and status.
Void
The circle pad and buttons work quite well for this game. The 3D is again layered, with your void floating slightly off screen. This mostly helps to keep all the background text from interfering with the beats. Having your status (hyper, mega, etc) on the touchscreen makes it easier to keep track of.
Runner
The dpad and buttons work very well (as they should) but the timing seem to be a split second off to me. But I think that's simply more because I'm used to the Wii controller and not a fault of the game. (EDIT: Having played Runner some more, it's definitely just the slightly different button layout. Now that I'm used to it, no issues) The levels seem to have a slight graphical refinement to them - for instance, instead of pink blobs for powerups, they are now well defined first aid symbols in translucent bubbles.
The 3D isn't really used at all besides the status bar up top floating slightly and your scores fading a little into the distance, and when you first start a level, the level name floats. I had to play some levels in 2D then 3D to really notice the any difference. It's very marginal.
The only thing annoying about runner is that the touch screen shows what power up level your at full screen (hyper, mega, etc) and flashes, bounces, etc. This is pretty distracting at first, but you get used to it.
Fate
The new control scheme (control stick to move and touchpad to aim and fire) certainly takes a little getting used to. Once you do get used to it, it does work, but I suck at the WiiWare version, so I'm not the best person to say if it works as well.
3D is hard to notice at first glance in this game except for powerups flying up and a little bit of depth.
Flux
Take everything I said about Beat, it applies here pretty much the same, except the layers aren't separated as much 3D wise.
Overall
These are the Bit.Trip games we know and love from WiiWare with the same great look, feel, and controls. The 3D is modest, and not noticeable sometimes, but does help out in Beat. If you need/want a portable version of the games, you can't go wrong. Myself for instance, I don't have my Wii at school, so it's great having these on the 3DS. If however you are fine with the WiiWare (or Complete) versions and don't need it to be portable, then there really isn't a reason to get this.
TL;DR Short version: The WiiWare games we all know and love, in portable form. Good controls. Modest 3d that helps in Beat.
Interface
On the Touchscreen you have the 6 games with icons the same as there WiiWare versions. Tapping one shows you the controls for the game. Choosing to start the game there is a very short load time then you have the same individual game menus as before, but most of them are in 3D.
Beat
You can either control via the stylus or the circle pad, with the circle pad being a waste of time, unless you have really fine motor control and are able to make micro adjustments. The stylus on the other hand plays very well and is quite responsive. Overall, I like the tilting of the Wii remote better but the stylus does work very well and you won't be dying because the control sucks, unless of course your stupidly using the circle pad.
The 3D works well with the game. It basically gives you 3 layers: The background, paddle and beats, score/status. The differential does make the beats really stand out compare to the Wii version. Of course, it is still fully playable in 2D, as they all are.
Core
Core isn't one of my favorites, but for what it is, it works well and the dpad and buttons work fine. The 3D isn't very noticeable, mostly there for your score and status.
Void
The circle pad and buttons work quite well for this game. The 3D is again layered, with your void floating slightly off screen. This mostly helps to keep all the background text from interfering with the beats. Having your status (hyper, mega, etc) on the touchscreen makes it easier to keep track of.
Runner
The dpad and buttons work very well (as they should) but the timing seem to be a split second off to me. But I think that's simply more because I'm used to the Wii controller and not a fault of the game. (EDIT: Having played Runner some more, it's definitely just the slightly different button layout. Now that I'm used to it, no issues) The levels seem to have a slight graphical refinement to them - for instance, instead of pink blobs for powerups, they are now well defined first aid symbols in translucent bubbles.
The 3D isn't really used at all besides the status bar up top floating slightly and your scores fading a little into the distance, and when you first start a level, the level name floats. I had to play some levels in 2D then 3D to really notice the any difference. It's very marginal.
The only thing annoying about runner is that the touch screen shows what power up level your at full screen (hyper, mega, etc) and flashes, bounces, etc. This is pretty distracting at first, but you get used to it.
Fate
The new control scheme (control stick to move and touchpad to aim and fire) certainly takes a little getting used to. Once you do get used to it, it does work, but I suck at the WiiWare version, so I'm not the best person to say if it works as well.
3D is hard to notice at first glance in this game except for powerups flying up and a little bit of depth.
Flux
Take everything I said about Beat, it applies here pretty much the same, except the layers aren't separated as much 3D wise.
Overall
These are the Bit.Trip games we know and love from WiiWare with the same great look, feel, and controls. The 3D is modest, and not noticeable sometimes, but does help out in Beat. If you need/want a portable version of the games, you can't go wrong. Myself for instance, I don't have my Wii at school, so it's great having these on the 3DS. If however you are fine with the WiiWare (or Complete) versions and don't need it to be portable, then there really isn't a reason to get this.