So I Decided to play through this on a whim since the last time I played it was on an iphone like 7 years ago and I wasn't even sure I'd finished it. I don't think I did, because this was such a bad time I wouldn't have forgotten. It convinced me to play all the Sonic that I can muster so here's the start of something:

It doesn't start off that bad. The visuals are fine enough and the first zone looks pretty nice: Castle ruins beautifully lit during both day and night. Playing through it doesn't feel right, though. The initial speed of jumping, falling, walking and homing attack are all annoyingly slow, and the animation adds to the frustration. Sonic at max velocity looks like he's stationary on top of a wheel that is too smooth. Just about everything is too smooth. These first levels are still okay, sadly all 3 have underwater segments. Famously everyone's favourite parts of these games that also happen to make the pretty backgrounds look bad for a good portion of the zone. It doesn't take too long for the worst offender of the gameplay, the special duo move, to sink in as it breaks up any and all momentum again and again. Going in and out of it plays a cutscene every single time and it gets tiring around the third. It's also very safe and spammable.

The rest of the zones don't look bad but not very good and there are no interesting twists really. The second is just a lot of snow with a one-note carnival detour, the third a desert with annoying tower climbs and the fourth a sky zone with the worst plane segment ever made. Sky Fortress act 1 is mostly an auto scroller with worse controls than back in Sonic 2 and after many repetitive screens you think it's gonna end but you're only halfway through the 6 minute slog. In my case it was about 15 because I died twice, fun times.

Bosses in 2d Sonic have always been pretty meh, but at least they were easy and mostly pretty fast. In most cases you can get in a bunch more hits than the free ones given in the obvious window between attacks. Risking a death for extra hits is rewarding and feels skilful. So let's remove that and make every boss a waiting game. Cool, thanks. Uninspired, boring, worse time wastes than the worst stages.

I rarely get nauseous playing a video game but the final level is almost unplayable. A run through rotating sci-fi bullshit where you can barely see Sonic for the spinning back and forth. I very rarely suffer from motion sickness in games but I was near throwing up going through this. The final boss is surprisingly interactive and somewhat challenging if janky. More luck based if anything when spamming the special fly move which felt most effective.

Sonic 4 Episode 2 is not solely miserable but definitely not worth your time. I don't recall episode 1, or any other (mainline) Sonic game for that matter, being this bad but we'll see.