Had a chance to play this today on Switch.... keep in mind this is a pre-release version so there maybe a patch coming that changes things... but for now this is how it plays:
It starts off with a cut scene that's just a movie file being played back, so you can see what looks like MPEG compression as well as other odd artifacts that look like a Bayer filter. Then it put me in some kind of Green Hill tutorial level, where every couple of seconds messages pop up, like it will remind you to press B to jump. Wow, I would never have figured that out on my own. Finally I got to the main area, Kronos Island, but I made the mistake of going up to a tower so it put me into this training area which is just a white background and a list of button combos at the bottom of the screen. Thankfully you can exit that by pressing -, but then it sent me back to the tutorial section for some unknown reason. Anyway finally I get back to where I can walk around and it's still popping up messages every few seconds, telling me to pick up items or something. I wasn't really paying attention, I just wanted to explore.
I realize the Switch is getting a bit long in the tooth so my expectations for the graphics were not that great, but Sonic Frontiers sometimes looks like a high res Saturn game. Polygons pop in at very close range and the game uses dithering everywhere, the dithering patterns are huge and remind me of the options in MS Paint from 30 years ago. Get up near the leaves and you'll see what I mean. I'm guessing the Switch was not the target hardware here.
On the plus side - the controls are decent, although they take some getting used to, and I like the music I've heard so far. You can tell they were inspired by Breath of the Wild, the "boost" gauge in the middle of the screen is just like Link's stamina meter and there's robot enemies called Guardians that drop gears when defeated. Framerate is usually pretty solid although it did dip a bit in busier areas. Performance seemed fairly similar whether docked or handheld although it's so zoomed out most of the time I find it much easier to play on the TV.
Anyway it's late here but I'll probably pick it up again tomorrow, despite the rough edges it's not the worst game I've ever seen. I mean, at least it autosaves, so it's better than NieR:Automata. The Internet is going to tear it apart for the graphical issues though.