Battlefield/Miiverse: No explainations are needed for that one.....
Big Battlefield: Heavily promotes camping on 1v1s, which never happens on doubles
Final Destination: No explainations are needed for that one.....
Mushroom Kingdom U: Nabbit can disrupt gameplay and is harder to get out of at higher damages
Mario Galaxy: Unique gravity and the fact that it is a walk-off (which means easy KOs with most attacks if close enough)
Delfino Plaza: It's obviously not neutral, but nothing seems wrong with it (all OP things are temporary)
Mario Circuit (Mario Kart 8): May add a wall, one walk-off side or a ceiling in certain transformations, but there is always at least 3 uncovered blast zones in which you can KO someone. Shy Guys deals good knockback, but not as much as Brawl's MC and are present in only 2 locations.
Mario Circuit (Brawl): Shy Guys can KO players easily (despite their predictability) + walf-offs = easy KOs
Luigi's Mansion: Small, destrucible caves of life (the sides of the mansion) can stop Charizard's Side-B, but abusing them can destroy them, which balances things out, IMO
Jungle Hijinxs: Dynamic stage, dual-plane system: front plane is neutral but can disappear for a short moment, back plane deals more knockback, but is much larger and has higher ceiling, balancing things out. Abusing cannon destroys them and deals you damage.
Kongo Jungle 64: reverted back to its 64 size, making it good for 1v1s again
Skyloft: See Delfino Plaza
Bridge of Eldin: Walk-off + King Bulbin destroying the middle part = over-usage of Meteor Smashes and easy walk-off KOs
Temple: TOO BIG FOR ANYTHING!!!!! Also has a cave of life at the bottom
Pyrosphere: FG-II Grahams, Zeros and Ridley. 'Nuff said
Norfair: Predictable lava, lava walls only appear one at a time, leaving the other side available for horizontal KOs
Port Town Aero Dive: See Delfino Plaza + apparently it has no ledges
Wooly World: Three different forms: two are walk-offs and the other one barely has anything, leaving easy occasion to meteor smash other players
Yoshi's Island: Spinning blocks, right wall covered by diagonal walk-off (making it a permanent semi-walkoff)
Great Cave Offensive: WAY TOO BIG!!!!!! Also the Danger Zones (glowing red sections) can KO at 100% or more
Halberd: Double Cannon is predictable, easy to avoid, but also easy to drag opponents into. Walk-off at the first 5 seconds, but doesn't matter due to the short time.
Orbital Gate Assault: Multiple layouts (Great Fox->1st missile->Airwings->Second Missile->Airwings again->Great Fox), missiles explodes after the same amount of time, everytime, making it predictable. Mini missiles deal no knockback and around 2% damage.
Lylat Cruise: No explainations are needed for that one.....
Kalos Pokemon League: Silver goop on swords chamber metalize anyone touching it, flame "geysers" in fire chamber never stuck characters in, it pushes them back where they came from and projectiles can go though. Rayquaza in dragon chamber and the flood chamber can be problematic, but are only temporary.
Pokemon Stadium 2: No explainations are needed for that one.....
Onett: Overly complex layout, blast zones unusually close, walk-off and that black van.
Coliseum: Walk-off = easy KOs
Castle Siege: Transforming stage, 1 of its 3 transformations is a walk-off, but the other 2 are neutral.
Flat Zone X: No explainations are needed for that one.....
Palutena's Temple: GIGANTIC!!!!! Multiple caves of life, southeast side is a perfoect place to easily KO with Meteor Smashes
Skyworld: Intact platforms = Caves of life, Broken platforms = No ledges and easy kills with Meteor Smashes
Gamer: 5-Volt deals great knockback (if you get caught) but is semi-predictable, randomized layout. May get banned later.
Garden of Hope: Only problem is the predictable Peckish Aristocrab (look for bubbles)
Both Animal Crossing stages: No explainations are needed for those ones.....
Wii Fit Studio: Walk-off = easy KOs
Boxing Ring: Walk-off = easy KOs, lights platform can deal great knockback and is easy to reach, but also gives incredibly easy KOs with attacks dealing vertical knockback
Gaur Plain: Metal Face + Huge gap in the middle, giving over-usage of meteors. Top platforms are walk-offs. REALLY BIG!!!!
Duck Hunt: Fixed Camera + 2D, 8-bit Duck Hunt Dog's intimidating laugh (it's also a platform, whether he's laughing or not), the tree's "bushes" are platfroms and so is the actual bush.
75 m: No explainations are needed for that one.....
Wrecking Crew: Unique mechanic of lowering the floors is only possible with the bombs (with deals no apparent damage nor knockback), barrels can trap opponents if they are under it when it lowers, but the bombs make it very predictable
Pilotwings: Sure, there is a plane switch at some point, but other than that, there's barely anything going on. (Small second-long hazards may show up, but it's difficult to get hit by them)
Wuhu Island: Patchable glitch discovered, but only seems to be possible with Ness's down throw. See Delfino Plaza for the rest.
Windy Hill Zone: Heavily promotes camping on 1v1s, which never happens on doubles.
Wily Castle: Yellow Devil
PAC-LAND: DO I REALLY NEED TO EXPLAIN ANYTHING ABOUT IT???? THAT STAGE IS DISGUSTINGLY BROKEN!!!!!!!