Pokémon Stadium

From Smash Bros - Wiki on Neoseeker

This constantly changing stage provides a fun, frantic and unpredictable battle arena. At first the stage may appear rather basic, but after a short time it will begin to morph into one of the following: A fire-based stage, a grass-based stage, or a water-based stage. Each form is decidedly unique. The fire stage is tight and confined, the grass stage has lots of new platforms and the water stage has a large windmill. The changing scenery can be confusing, so the key to winning here is being able to adapt faster than your opponent.