Awesome Music: As a Sonic game, this is pretty much a requirement. Although some may consider Episode I's instruments to be full of a sound resembling that of dying cats, Episode II's usually don't have such sounds.
And before that, the fight against Metal Sonic on the roller coaster ranks as one of the franchise's most intense boss battles yet. It's a high-speed chase up and down the coaster's tracks where you have to dodge Metal Sonic's energy attacks, spin-dashes, and sudden pitfalls while desperately trying to strike him down. In this fight, Metal Sonic pretty much throws everything except the kitchen sink at you, and when you've whittled him down enough, he goes completely berserk and tries to blow the roller coaster to smithereens just to kill you.
The final boss of Episode II. On top of being really funnote Although, that's not to say that the others in the game weren't, it's one of the most creative bosses in any of the Sonic games thus far. The awesome music playing also really helped.
Casino Street Act 2. The console's Road of Cards version features large groups of cards that hand out items as they're flipped, meaning you can take about a dozen lives every time you play it. The mobile version of Act 2 is instead an effortless mini pinball table you have to collect points in.
White Park Act 2 is an easy rollercoaster to run around, in contrast to the platfoming featured in the other acts.
Death Egg Mk 2 Act 1 has two boss fights, but also features surprisingly simple level design you can run freely through.
Broken Base: This game has probably gotten the biggest amount of praise and backlash at the same time with just three seconds of footage shown with a tons of people analyzing and nitpicking every aspect they can get their hands on judging from the trailer alone.
Later, the game gets delayed for tweaking, fine-tuning and an iPhone release. Many of the fans find it a time for rejoicing, as they have hopes that Sega is actually paying attention to the complaints. Other fans are upset with Sega for hyping the fanbase up over a delay, and they felt the game would've been fine coming out as it was.
On a smaller scale, some people think that the music was a bit stifled and wasn't mastered well.
No Wii release for Episode II prompted this, as Wii owners questioned what made it impossible to do on the Wii when the first episode worked fine - It's largely down to the new graphics engine & better quality music files making the game too large for the Wii Shop. This has conversely opened up a camp of people blaming the Wii for the poor graphics & music quality of Episode I. Another subset of the Wii owners are complaining that because Episode II isn't seeing a release on the Wii, they won't be able to access Episode Metal without repurchasing Episode I. (That said, nothing has been confirmed about a Wii U re-release yet, so there may still be hope.)
Sonic 4's eventual cancellation and the team's lack of hope that it will continue split the fans. Some say that the project was ultimately a failure and deserved to be cancelled as the developers ultimately failed to find what made the classic games so beloved and tried to shoehorn new developments into it. Others believe that the series was unfairly evaluated and that it should have been concluded, especially with Episode II fixing much of the perceived problems with Episode I.
Contested Sequel: Both fan and critic reactions for both games vary when they're asked to compare them to the previous 3 installments.
Critical Dissonance: While this has always been a common trope with the series, Sonic 4 takes it to a weird level. Critics gave Episode I good to okay reviews while most fans view it as an inferior game. Meanwhile, most critics ripped into Episode II, yet most fans view Episode II as a marked improvement over the original.
Ear Worm: This game has some too. In particular, the "Pinch" boss music in Episode I (and standard boss music in Episode II), a nearly 20-second loop of repetitive notes to the point where some people think it's shorter than it actually is. It's fine as for its use as a boss theme, but it ends up being used as the EGG Station's BGM until you reach the final boss, which of course takes longer to get through than finishing off an angry end-of-the-stage boss.
Even Better Sequel: Most fans consider Episode II far superior to Episode I thanks to its vastly improved graphics, less derivative level and boss design, a new physics engine that more closely resembles the Genesis games, and the ability to play as Metal Sonic.
Faux Symbolism: The final boss of the Death Egg mk.II Zone is a heart. A realistic, beating, human heart.
Game Breaker: You can press Retry before time runs out in special stages, providing infinite attempts at each Chaos Emerald as long as you don't touch the exits.
The Rolling Combo in Episode II. Immune to almost every hazard? Check. A constantly moving Spin Attack that can take down even Snowy in one hit? Check. Makes the Stardust Speedway remake race incredibly easy? Check.
Also, as usual, Super Sonic. This time around it's taken even further since he can no longer drown (meaning the only things that can kill him are Bottomless Pits and being crushed), he automatically lights up Lost Labyrinth Act 2, and forces the slot machines in Casino Street Act 1 to come up as jackpots.
Super Sonic got even worse in Episode II, as now he's playable in boss battles and he does DOUBLE DAMAGE to all bosses.
Goddamned Bats: All of Casino Street Zone has Batbots everywhere, and Mad Gear Zone has the Slicers that'll ruin your day. Asterons, also in Mad Gear, are surprisingly less annoying. Shellcrackers are less threatening too compared to Metropolis Zone.
Episode 2 did not come to WiiWare. The hatemail came in droves.
Taken even further after the first gameplay trailer of Episode 2 was released and the confirmation that Tails won't be playable in Single Player mode.
The "Episode Metal" announcement has induced this even more with Tails fans.note Tails isn't playable outside of 2-Player Co-Op mode, but Metal Sonic is playable in single player and gets his own story campaign to boot. The fact that you need to own both Episodes 1 and 2 in order to unlock "Episode Metal" hasn't sat well with some either; especially Wii owners.
It's the Same, Now It Sucks: What part of the fanbase thinks of the first episode. The stages, for example, have been accused of being carbon copies of the Genesis/Mega Drive stages instead of original stages like they actually wanted.
Scapegoat Creator: Dimps became this after this game, after a successful run on the Sonic Advance Series and the Sonic Rush Series. With every Sonic game they have made since then (most notoriously the 3DS version of Sonic Lost World), the games's shortcomings have been blamed on them, even though it was Sonic Team's current leader who admitted that he wanted the game to have a different feel than the Genesis games.
Scrappy Mechanic: The camera is just a little too close to Sonic for some people, causing people to barrel along without having enough of a view for what's headed for them.
The Homing Attack from Sonic Adventure onwards bolted onto this decidedly old school game also qualifies, though most people aren't really upset about lock-on dashing as they are the horizontal leap you can take when you're not even locked onto anything.
Sonic uncurling in mid-air after flying off a ramp or attacking an enemy. It's designed to force players to rely on the homing attack, but if they're a little too familiar with classic Sonic gameplay, they'll be shedding rings at least five times per act.
His acceleration feels significantly slower than the classic Sonic games, or even the side scrolling Mario games for that matter (though this is one respect in which Sonic games were always slightly slower, it was less significant). Good for the Scenery Porn. Bad for a character who is supposed to be fast. Compare the generally faster gameplay in the classic stages of Sonic Generations.
Not being able to play as Tails outside of co-op mode in Episode II. Most stages can still be completed by having Sonic just stand there and using the Rolling Combo when needed, but some are still impossible to complete without controlling Sonic directly.
So Okay, It's Average: The general opinion on Episode I. While it's a perfectly playable game on its own, it completely fails at being a follow-up to the classic games in that its core gameplay is similar to Sonic Rush without the boost, and it tries to mask this fact by having derivative graphical designs from stages in previous Sonic games.
Surprisingly Improved Sequel: In the case of people who though Episode I was mediocre at best. When they said they were improving Episode II, they weren't kidding: better graphics, better stage designs, better physics, the ability to use Tails as a power up and play him in multiplayer, more creative boss fights, Red Rings, small nods to older games, and Episode Metal to name a few.
Also better music that relies less on the Sonic 2 snare sound as well as fewer "gimmicks". There is nothing like the torch puzzle or the water puzzle in episode II.
That One Achievement: In Episode I on the XBox 360, you get an avatar award for collecting all of the rings in the pre-credits area. What makes this annoying is that Sonic moves on his own, so you're done if you miss any, and if you don't get it, you have to finish the final stage all over again just for another shot at it.
That One Boss: The Death Egg Robo from Sonic 2 returns as the final boss. And he's even harder in this game, even though you actually have rings this time when you fight him...
And before that, the boss of Lost Labyrinth Act 3 can be really hard for some as well. Make one mistake and you're squashed by the walls.
The Episode 2 final boss is shaping up to be this. As is Metal Sonic's Badnik Carrier.
Every Metal Sonic boss fight. If your relflexes aren't up to par, you'll find yourself dying a lot.
True toDimps tradition, the special stages in Episode II range from trivially easy to somewhat difficult until you get to the last one, which is nearly impossible.
Same goes for Episode I. It has the most complex design and a ton of bumpers next to exits. The low time limit doesn't help things. The physics are odd as well: Sonic bounces when hitting walls and when grounded on them, he sticks too much, which results in very imprecise, time-wasting controls.
Sky Fortress Act 3, from Episode II can be difficult for some people, especially for badly coordinated players in 2-Player mode.
They Changed It, Now It Sucks: A lot of the complaints from the three seconds of footage alone range from Sonic having the modern design in a sequel to the old school games, Eggman not being called Robotnik, that it looks like it'll become a "Sonic Rush 3" and that it has the Homing Attack (more specifically, the game's over-reliance on the move). Some are even complaining about how the game is using a sleeker HUD instead of reusing the admittedly blander one found in the older games. And of course, the physics.
This is what reviewers seem to think of Episode 2 in comparison to the first episode.