The Sonic franchise is a strange one because "fans" hate the majority of the games. Sonic Forces is often regarded as another bad game, but I think it's just mediocre.
The early Sonic games were really about momentum, and not about "going fast" which is a common misconception. However, people's misconceptions keep leaking into the modern games' design. In a platforming game, how do you allow Sonic to go fast? Reduce the frequency of enemies and obstacles? give the player a method of navigation/attack that allows them to be imprecise? That's what you often get in these games, and then the result is - the game basically just plays itself.
You often get long stretches where you are just watching your character run down long straights, go through loops, bounce from spring to spring. Then in other sections, you just jump at the end of a platform, repeatedly tap jump to homing-attack multiple enemies, or home-in to the next spring. There's also a dash that can plough through enemies. Essentially, the design often puts the focus on speed and spectacle but at the expense of challenge. The emphasis on speed means the levels are often short, and cumulatively the overall game is short.
There's still elements of jank where the jumping may feel a bit inconsistent. The levels can also be a bit unclear like when you reach the end of the platform and you think you must have to jump, but really the game wanted you to keep running to hit a hidden spring. Why have hidden springs? It's something that has always annoyed me about Sonic games. I want to react to things that I can see, not have to take leaps (or runs) of faith. The trial and error is no way near as bad as other games though.
There's a couple of simple Quick-Time-Events (QTE's) which I think you might not be able to fail; it's merely there as an opportunity to give you bonus points. There's moments where there's a lot of action in cut-scenes but then no QTE which makes me feel like they just forgot they had that feature earlier in the game.
In regard to the recent games, I thought Lost World was a bit disappointing, and although I didn't play it, Sonic Boom was regarded as even worse. Sonic Forces moves back closer to what we saw in Generations (which I think is one of the best Sonic games); it has the mix of 2D side-scrolling, 3D gameplay, and the lane-changing gameplay where the camera is positioned behind your character.
Just like Generations, there's modern Sonic as well as the smaller and mute classic Sonic - although I feel like he was just shoe-horned in for no reason. It's probably for nostalgia like they always do "hey! remember Green Hill Zone?", "remember Chemical Plant?". Do we really want the Green Hill zone again? Surely we want new ideas.
A new idea is that you also create a character who others call "Rookie". Initially, your options for accessories are limited, but you unlock loads of these as you complete the levels. For your character, you choose an animal such as dog, wolf, bird, bear, hedgehog and a few others, then customise ear, eyes and nose, and choose skin colours. Your character can also run fast so he isn't that different to Sonic. He also has a gun type weapon which you can switch out called a Wispon. This can defeat enemies quickly and also has a power such as launching you vertically, or homing through sequences of rings. This is sometimes needed to find the secret Red Rings in each level.
I have been saying for years that the life system needs to be binned because it adds no value, and they have finally done it. Now when you die, you always restart at the checkpoint.
Often in the Sonic games, the voice acting is bad, but this one seems like they actually have a better script and deliver the lines with better timing and tone. The weird music that people seem to like is here, with the main theme sung by Hoobastank's Doug Robb.
The story isn't that interesting or convincing though. You are told Sonic is captured and is being tortured (which is a bit dark for a Sonic game), but yet he is rescued very quickly and still reeling off his wise-cracks. I got the impression there was a bit of a Star Wars influence with Dr Robotnik taking over the universe and a small group of rebels planning to destroy his Death Egg (Death Star). Then a powerful enemy known as Infinite wears a mask (Darth Vader).
Some people will replay the levels to improve their score but I thought the grades were rather generous. I got many A's and I didn't think I was doing anything worthy of that (not collecting enough rings, finding secrets, or not going fast enough). There's also "Daily challenges" but since these can be the likes of "change your shoes"; it's not really a challenge - more like general tedium.
Graphically it looks really good. There's a great level of details in the background (although I suppose you miss quite a bit of it when you are going fast).
It may not be challenging, and the game design mainly forgets what Sonic games should actually be, but it's actually one of the better Sonic games in the modern era.