After settling in Green Hills, Sonic is eager to prove he has what it takes to be a true hero. His test comes when Dr. Robotnik returns, this time with a new partner, Knuckles, in search for an emerald that has the power to destroy civilizations. Sonic teams up with his own sidekick, Tails, and together they embark on a globe-trotting journey to find the emerald before it falls into the wrong hands.
This movie contains 10 potentially triggering events.
A scene early in the movie contains somewhat intense strobing lights. There are various other minor instances of flashing lights and colours throughout the movie.
When Sonic and Knuckles first meet, they are not friends at first, and Knuckles tries to kill Sonic, in part by choking him. Sonic survives this ordeal, as well as others, and Knuckles learns that he was mistaken about Sonic knowing the location of the Master Emerald and that he was tricked by Robotnik. The hedgehog and echidna are friends now.
Not really, there’s a scene where Sonic sets up a puppet to fool Tom and he uses a voice recording. In the recording, Sonic says that he ate chilli dogs and he now has to constantly fart, while making fart noises. In a following scene, Sonic says “I should’ve used real farts”
Guns are often used, but nobody is ever hit by a bullet. The only ones fired onscreen are either cartoony weapons or explicitly non-lethal. There is a scene where a character appears to take a bullet for someone, but it is revealed within a few minutes that he was only hit by a stun gun/taser and not injured.
No real animals are hurt or killed, but Sonic, Tails and Knuckles are all cartoon anthro animals explicitly described as a hedgehog, fox and echidna respectively, and they are frequently put in danger and/or badly hurt. There is also a scene where a dog is implicitly close to a violent confrontation, but said dog is never seen during the fight and returns at the end of the movie completely unharmed.
There is a scene where Sonic and Tails are threatened with being thrown into fire, but at no point do they or anyone else actually make contact with fire or suffer burns.
As noted in a previous comment, Knuckles’ handshakes comedically break bones.
On a more serious note, there is a scene where Sonic sustains multiple injuries, including an implied broken leg and an implied broken arm. He goes into his Super form soon after, which, just like in the games, heals all his injuries (and looks spectacular and gives him strength beyond normal).
Robotnik falls a long distance at the end of the movie and is not seen afterwards, but no impact is shown and it's very strongly implied that he survived the fall and escaped offscreen.
Near the ends two characters refuse another’s request to get safety insisting they stay by their side, implying they’re willing to die alongside them albeit they end up okay in the end
Longclaw's death from the first movie is alluded to and briefly seen in flashbacks, and it's implied she was a parental figure to Sonic. Tom and Maddie, who also act like parents to Sonic [with the father-son dynamic between Tom and Sonic mentioned several times], are put in danger and at one point seem like they're going to die, but they both survive the movie with no serious injuries.
While it isn't cheating, one character is revealed to have been lying to their fiance the entire time they've known each other. However, they express that the love they felt for their fiance was real, and the two make up. These characters are relatively minor and don't get any screentime after making up, so some viewers may find the resolution to be in poor taste.
A black character appears to die dramatically, but it is quickly revealed that he wasn't actually hurt. Nobody dies in the movie aside from animal characters in flashbacks.
There are numerous instances of cars crashing, including one where a car goes over a cliff and the characters in it escape before it lands, and another where a truck flips over with passengers in it. Nobody is severely injured in a car crash, but there are a lot of close calls.
Knuckles is hit by a car early on, which throws him and stuns him for a while, but he recovers quickly. There are also a lot of scenes where cars narrowly miss colliding with people, but only Knuckles is actually hit.