Well at least I now know why this demo took so long to download.
Anyway, impressions!
As others have stated what we've got here is mostly just a tutorial stage, still there's quite a bit to take away from this demo.
While it's obviously apparent that Puppeteer takes a heavy stage show approach to how it's presented what's worth noting is that it takes this idea and truly runs with it, what you'd consider cutscenes are intertwined with the gameplay, scenes shift frequently with the areas being plonked down before you, it's all very impressive looking.
One of my doubts i've had about this game coming from the trailers is that all the emphasis on being a stage production would hamper the flow of actually playing it between characters being all theatrical, this demo pretty much confirms that at least in the early stages that it's a bit stop and start at times, even switching between small areas of platforming can come with the lavish setup of a new stage scene with the main character performing an action independent of the player while all the bits are falling into place so at times you kind of had to wait until everything was all in place before control is returned to you. But the later area heading up a winding tower used a different format, since the gameplay area wasn't in need of constant shifting it flowed a lot better.
There's been a kind of unwarranted fear of floaty jumping because apparently being on the same console as LBP is an ill omen or something, rest assured the jump is fine and has a nifty sound effect to boot. Kotaro's basic actions are as simple as they come, you move with the stick with momentum not really looking not be much of a factor for both running and jumping, he has a basic jump, he can duck and can grip onto platform edges meaning that you could potentially pull yourself up form misplaced jumps or reach areas just a bit beyond his jumping height.
What makes this game stand out on a mechanics front are its two core elements, one being the various masks, the other being the scissors.
The masks operate as both your "health" and in some cases extra abilities, if you get hit your current mask goes tumbling off and you have to scramble to pick it back up in like 5 seconds before it vanishes, if you do lose it you'll switch to one of your other masks in reserve, presumably if you lose all your masks you lose a life. As far as the demo goes you can hold three masks at once, any new mask you stumble across replaces the one you're currently wearing if you have no spots left. The game touts 100 or so unique masks, only a select few of these appear to award Kotaro with any significant abilities. The ones on hand in the demo are more like taunt buttons as far as i'm aware mixed somewhat with the LBP sticker concept, perform the mask action/taunt in a specific place relevant to the mask and something might happen like when I used the Spider mask's action by a web and got carried off to a bonus stage by the big mother spider, said bonus stage was just an opportunity to nab more moon sparkles or whatever they were called, basically the games equivalent to coins.
The scissors come in right at the end of the demo so unfortunately there's not too much to say about them right now, you can cut certain materials and attack enemies with them, by cutting across materials you can manoeuvre Kotoro into places where his jump wouldn't carry him and effective cutting can be used to trigger events in the stage area which is pretty much the angle of the the scissors tutorial here. It's worth pointing out that using them in the air even with nothing to cut causes a brief delay before falling which is handy for extra evasion.
The game has a side mechanic where the right stick controls an assistant character (In this demo the witches cat, I presume the small red princess...thing takes this role for most of the game). Basically you move over objects and press R2 to investigate them, mostly it just releases the old moon bits from objects in the background though sometimes it's needed to trigger progression. Can't say i'm a fan of stopping to search barrels and such, a second player can take on this role much like the co-star in Super Mario Galaxy allowing for some light co-op antics.
The game looks to have a lot of fun with its theatre setup, characters lunging right to the forefront of the screen, an audience that laughs when your messing around with the scenery reveals other puppet boys that then scramble to escape, gasps at various hazards and plays into the dialogue sequences.
With all this i'm wondering what this games main angle is, of course it's hard to tell from just a demo of the games opening but it really pushes the theatre stuff, whether it will be to the detriment of the gameplay itself remains to be seen, at this stage it's not quite a full on "hop and bop" platformer (though it leans more to this angle) or action platformer, it's not really a puzzle focused one either. It may very well be a more unique entry to the genre that uses some basic platforming ideas to deliver its colourful and quirky stage show.
I'm sold on trying it when it releases but i'm not expecting something that's going to top the rest of this years big platforming outings as far as gameplay is concerned. Yet it looks like it'll be fun, possibly a bit breezy in a good way (see: Kirby series). Of course I could be wrong entirely and the game turns into straight up precision platforming hell.
Anyway it's something different and that's a good thing, hopefully the full game can stack up to its presentation.