Super Smash Bros. for Nintendo 3DS / for Wii U has four Pokémon stages, split between the two versions. Here are their features, according to Poképédia.

The Unova Pokémon League.

Prism Tower (3DS)

The battle starts at the foot of the Prism Tower, on the central plaza of Lumiose City, during the day. A platform then carries the fighters to the top at sunset, and then night falls. Magnemite, Zapdos, Helioptile and Yveltal can pass by in the background.

Unova Pokémon League (3DS)

The stage changes from the Pokémon League to N’s Castle. Reshiram and Zekrom attack it with Fusion Flare and Fusion Bolt, while Milotic, Whimsicott or Shaymin make a simple cameo.

Kalos Pokémon League (Wii U)

A large platform slides through the four chambers of the Elite Four. Each has its own hazards, such as the swords in the Steel chamber, which you can stand on but whose blades hurt, and its own Pokémon, including an active Legendary.

ChamberBackground PokémonLegendary and effect
Dragonmark ChamberGarchomp, Hydreigon, Axew, DragoniteRayquaza crosses the stage; sparks signal its path
Ironworks ChamberSteelix, Scizor, Klinklang, HonedgeRegisteel buries fighters by leaping and makes the swords spin
Blazing ChamberBlaziken, Infernape, Tepig, PyroarHo-Oh creates two columns of fire
Flood ChamberBlastoise, Wailord, Piplup, ClawitzerManaphy turns the central platform into a typhoon

Pokémon Stadium 2 (Wii U)

Brought back from Brawl, this Kanto stage, inspired by Pokémon Stadium, transforms as the battle goes on: Flying type, with a wind that lowers gravity; Ground type, with a mountain in the center; Ice type, with a slippery floor; Electric type, with conveyor belts toward the edges. It is unlocked by finishing a specific event match.