These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Anti-Climax Boss: After the grueling Metal Sonic battle, you're treated to a 15-second fight with Dr. Robotnik in his Powered Armor, who can almost effortlessly be taken down, as he can only do a PPP combo and a throw. Combine this with the fact that you start with a perma-Hyper Mode to encourage you to really let loose on him or the Death Egg II will self-destructwith you in it if you have more HP than Robotnik when time runs out. What's odd is that Robotnik -does- have a full (and quite deadly) moveset, as using cheats to play as him reveals, he just doesn't use it because it would be unfair considering the time constraints.
Cult Classic: While not the most well-received spin-off of the Sonic the Hedgehog series (and more-or-less a "Fighting Vipers with Sonic the Hedgehog characters" game), it does have a cult following for being an obscure Sonic the Hedgehog fighting game.
Fridge Logic: Of course there's the infamous 8 Chaos Emeralds bit, which was an excuse to have eight main fighters, but then you never actually fight a character who has the eighth emerald (normally this would be you, but you don't start with any Emeralds); instead your character gets cloned by Dr. Robotonic and you get the last emerald from the resulting eighth fight. So.. One of your emeralds was cloned too?
Game Breaker: Sonic's spin-dash move, which deals heavy damage and is fast-hitting.
It's Easy, so It Sucks: The most common complaint against the game is that it's very easy compared to most fighting games. Some even claim that you can win by holding down one button.
Polished Port: The Model2 Collection's Updated Re-release on PlayStation Network and Xbox LIVE Arcade, as it has the Dummied Out characters added (though only a few, not all of them), online multiplayer, and a Sound Test function by using the trigger buttons on the controller.