The hardest Sonic game I've ever played is Sonic 2 for the Sega Game Gear. That is because the first boss always kills me. In other words, GAME OVER.

SonicKnuckles98 : I know you are a new member, but please do not post threads that are not reviews in the review section.

I will move this over to the video games section for now.

As far as difficulty goes, I would say Sonic 2 or Sonic CD are the most challenging, although I don't find ANY of them particularly hard outside of a stage or two.

the hardest sonic game is death egg zone I defeated silver sonic and then at first I can't beat robotnik with head I i targeted the chest it's hard for me I keep hit the chest that's is the hardest game in sonic the hedgehog 2

It has to be a draw between Sonic Hedgehog 1 the original and Sonic and Knuckles. Sonic and Knuckles is alright till the Egyptian themed Zone, the second part with all the Ghosts that murder you if you don't be quick with turning on the lights. And Sonic 1 has Labyrinth Zone, with slows down Sonic heavily, making him vulnerable to more deaths.





 

Guys, please don't laugh at me. But...

Sonic Heroes. Really.

And it shouldn't have been so hard. But due the oversensitive controls, I died so many cheap deaths. More than even in Sonic 2.

Nothing beats Sonic 06 or 3D Blast. Sonic 06 glitches me out, while Sonic 3D Blast has sloppy control!

Already played Sonic 2 and I think is the hardest sonic game I ever played.

Sonic Adventure 2 Battle.
The later stages get absolutely brutal (especially the final ones in Hero and Dark Story). The Treasure Hunting stages are insane to try and do in a good time as well, especially the later ones, since the hints are so vague and the area is so HUGE.

I like Sonic 3d blast a ton but it has really bad control so it was the hardest for me to beat. I also had a bit of trouble with Sonic Generations.

I think the hardest Sonic game is Sonic Riders: Zero Gravity for the Wii because the controls are extremely hard to get used to, and when you do get used to it, it is still clunky.

I think Sonic Lost World for the 3DS is the hardest Sonic game I have ever played. The enemy placement was horrendously all over the place and the level design made me feel like I wasn't playing a Sonic game. This was the first Sonic game I put down since Shadow The Hedgehog the video game.

Hardest game due to actual difficulty for me would probably have to sonic 2 on the game gear. Especially if you want to find all of the chaos emeralds. The size of the screen is truly what makes it difficult and it has some pretty hard platforming considering it is a sonic game. I would also say that some of the bosses are pretty tricky as well.. 

A few people here have said sonic 2 and i can not really understand why, I honestly think it is the easiest sonic game there is. I mean death egg is perhaps hard the first time.. But all you do is hit him twice run to one side avoid his attack and repeat  

I would actually say the hardest game would be sonic spin ball.. But that's not really a main sonic game.. Robotnik's mean bean machine can be challenging as well.. 

Hardest game to play though would go to sonic genesis.. The sonic 1 port on the Game Boy Advance.. That game is just evil to play and horrible.. It gives me migraines it is that bad.. There really is not a single decent feature about the game besides the fact it is sonic 1... How they messed up a port to a superior system i will never know. 

The hardest sonic game I ever played was Sonic CD. I still have yet to beat it but, I am on a mission to do so.

The original Sonic the Hedgehog, probably just because of the limited continues. I played Sonic 2 a lot as a kid and got pretty far, but I hardly get anywhere in Sonic 1. ...Seems like Sonic Spinball was also really hard, but I haven't played that since I was a kid. And Sonic and Knuckles was hard... Basically all of the originals (except 2) that didn't have unlimited continues / saving were super hard.

The hardest sonic game for me was Sonic Riders. I pretty much never really figured out the controls very well and I'd almost always get last place. I've never really been very good at racing games, so I was already at a disadvantage. It's still fun, but I don't think I'll ever be able to beat it.

Honestly, The hardest sonic game is Sonic R. 
It was a terrible sonic racing game with horrible controls, bad level designs, and just misplaced soundtracks that didn't really have that sonic feel to it