This arena is set inside a stone tower (so weather, SolarBeam, Thunder, Moonlight and Morning Sun are unusable). Digging and seismic moves are not allowed. There is also no external water source.
The tower is full of green goo and there are platforms along the edges. Here's a diagram for you:
When a pokemon is released, the trainer must specify which platform it starts out on. Also, pokemon may use the command
Move to platform X. Which platforms the pokemon can access depends on which platform the pokemon is on and their current speed. The distance they may travel in terms of number of platforms is speed/75, rounded up to the nearest whole number, max 4. So, for example, if Blaziken is on platform 5, it can travel to any platform between 3 and 7, whereas Steelix on platform 5 can only travel to platform 4 or 6. This command costs 3 energy per platform traversed (so the Blaziken would pay 6 energy to travel from platform 5 to platform 3). This command is not subject to the consecutive energy penalty and cannot be encored or disabled but Taunt will work against it. Finally, contact attacks cannot be used unless the user and the target are on the same platform.
At the end of the round, one platform will go into the wall (randomly chosen, all with equal chance but never the same platform on two consecutive rounds). Any pokemon on that platform will fall into the goo below (including flying and levitating pokemon). If a pokemon falls in like this, it takes 20 damage and its first action must be
Get up onto platform X (all platforms are reachable in this scenario except the one that disappeared). This command costs 10 energy, is not subject to consecutive energy penalty and cannot be encored or disabled. Falling into the goo cures a pokemon of sleep, freeze and taunt, but if it is fully paralysed when it tries to get out of the goo, it takes another 20 damage and it must try again.
Once a platform has gone into the wall, it stays there for one round and emerges at the end of the round (at the same time as another platform going into the wall). Pokemon cannot move across a hidden platform unless they can fly or levitate (so Blaziken can't travel from platform 5 to platform 3 if platform 4 is hidden) and obviously they can't stop on a platform that's not there.