I just played it for about an hour. I ran around the first level for forty minutes or so in docked mode before completing the objective and then switched to handheld for the next one.
It's rough. The framerate dips a lot. Anything that isn't in your immediate vicinity (collectibles, NPCs, details like birds hanging out) animate at a much lower framerate, which is always a pet peeve of mine. The framerate feels like a solid 30fps as long as your in a small enclosed area with no other characters, but the first level is pretty open and only has a handful of areas like that. Anytime there's anything going on the framerate is all over the place. Even if there's not a lot going on around you it stutters noticeably if you swing the camera around too quickly.
This is my first time playing the game so I don't have any point of comparison, but it feels like there's missing animations. The worst I've seen is a cannon in Mafia Town that acts as a shortcut. You jump in and it shoots you through a set of doors, through the center of the level, and out through another set of doors. It seems like there should be an animation of the doors being blown open but instead your character just clips through them. Maybe it's like that in the PC version too, but it looks lame.
There's a lot of little things that make it seems like the devs just didn't put a lot of care into the port. The game has a title card when the game starts up and before you enter the first level and it looks like they used a crappy low-res jpeg, it's just a static 2D image and it's still pixelated and blurry. The hourglasses you collect (they seem to be this game's version of stars in Mario or puzzle pieces in Banjo) look like they animate at a really low fps even when you're standing right next to them. Some areas feel like they could have used some more work. There's a little scene in the first level where some characters are lighting off fireworks in a plaza and the framerate just completely goes to shit there.
Everything looks noticeably worse in handheld mode. Some games look sharper in handheld, but this is definitely, definitely not native res and it shows. Aliasing is way more noticeable (and it's already not great docked). If you platform up to a vantage point everything in the distance is a blurry mess. Fifteen minutes of experimentation was enough for me, I'll definitely be playing docked.
All that I'm excited to keep playing. The dialogue is charming, the art direction is good even if the technical side of things is disappointing, and the controls feel great so far. Maybe things change later but I'm getting an early Psychonauts vibe so far where it's more about exploring than precision platforming, so hopefully the stuttering won't make the game frustrating to play. I don't regret buying it, I've been curious to play it for a long time and I don't currently own anything else to play it on, but if you do have options I would strongly suggest you take advantage of them.
Edit: Load times are also very long, but it didn't bother me. It loads when you start the game up and when you enter a level, I didn't time it but I would guess it took somewhere around 45 seconds each time. Not ideal but once you're in a level there's no loading.
