The demo for My Little Investigations is out. It's actually been out for a few days, but I forgot about it during all my finals. Anyway, you can get it here. There are some bugs that people encounter. One, a "could not find data folder" bug, seems to be common and here is a fix for that. I didn't encounter any major problems once I started the demo.
You can find impressions of other people here.
My impressions (I wrote them down as I played through, so they're a bit disjointed):
First, I love the presentation. It looks like the show. The music doesn't really tie into the show, but I enjoyed it and never found it annoying. It fits in well with each part of the demo. There is one part where the music randomly cuts out, though. I don't know if others had this problem or if it was intentional, but it felt out of place. While characters are talking, you'll see them actually move their mouths (though this isn't done perfectly) and change positions, and even when idle they'll still blink so they aren't completely static. That's a nice touch.
There are breathing/blinking animations when Twilight is just standing there. The walking animation is good. Twilight's hair moves while she walks, which helps make it seem more natural. She doesn't ever blink when she's moving though. I have no idea why I noticed that. I noticed that in the places you can visit, you see no ponies except for the ones relevant to the case. It makes Ponyville seem empty and abandoned. Also, there is no full screen mode. Not a huge issue, but it would be a nice option.
Everything is controlled with the mouse; there are no keyboard controls. I think they would be a nice option, but the mouse controls function well enough. It is basically impossible to see where you can and can't go without walking over to that part of the map and seeing if you get stopped by an invisible force. Some indicator would be nice. There's also no indicator for what is evidence and what is just part of the background. I got a bit click happy on things that I thought were evidence, but turned out to be nothing.
I didn't care for the voice acting because it sounds like the voice actors are trying too hard and it comes across as forced. Lots of other people like it, but I'm glad there's an option to turn the voices off. There are a few problems with the voices that I noticed; a few lines seem to be missing (but you can still see the text), and the volume isn't consistent which is annoying. Near the beginning, there is a reference to the show that is so forced and awkward that it made me cringe.
The demo starts off with an unskippable cutscene that basically tells you what happened, which is rather unfortunate. It is well done though. The reason why Twilight is investigating something is actually addressed, and it makes sense. That was a small detail, but I felt like it was a good addition. There was one part of the case where I got frustrated, and ended up stumbling across the solution on accident as I fumbled around with the evidence. That might have just been me being stupid though. The case is very short, and once the demo ends the game window abruptly closes.
Based on what's there, I think the game has potential. There are some things they could change to make things clearer to a newbie like me (unless I'm just dumb, which is entirely possible), but they did a pretty good job of explaining most parts of the game. I did enjoy playing through the demo, and I'd like to see more of their Equestria (the areas you can visit are very limited). Sadly, I don't think I'll enjoy the voice acting in the final game. I can tell that they aren't the actual voice actors, and that drives me nuts. I'd like to play the full game before I judge too harshly though.