Following the introduction of the Mega Evolution mechanic in Pokémon X & Y, Pokémon Rumble World is the first Pokémon Rumble game to use it. When you have achieved the ability to Mega Evolve your Pokémon, you will be able to get the option on the touch screen of the Nintendo 3DS while in a stage. Once you reach Rank 33 and complete the challenge, you will receive the Stone Shop that lets you give a Pokémon a Mega Stone for 5 Poké Diamonds. Then, if you press the button with a Mega Evolution-capable Pokémon, a cutscene will occur where your Mii activates their Mega Ring and the Pokémon will Mega Evolve.

When your Pokémon does Mega Evolve, it'll create a small shockwave damaging any Pokémon in the immediate viscinity, and will increase your Pokémon's stats to match its Mega Evolved form. This lasts for the duration of the match.

A returning feature to the game is the Wobbly feature. Sometimes, you will find the Pokémon will suddenly have some knockback and begin to wobble. When it is wobbling, if you knock it out, you are guaranteed a capture. This is especially useful on Boss Pokémon which have a very low drop rate for capture. This is completely random with each hit on a Pokémon, but there are a few ways of increasing chances.

Wobbly Tree: In the store, purchase the various levels of Wobbly Tree. With each successive level, up to Level 8 at Rank 63, you will have an increased chance of making a Pokémon Wobble.
Gutsy: If your Pokémon has the Gutsy trait, it has an increased chance of making a Pokémon wobble
Pokémon Moves: There are several moves that have an increased chance of making a Pokémon wobble. Focus Energy will increase your chance for a short while, while Spacial Rend, Frost Breath and Storm Throw have got an increased chance as standard
Boss Pokémon: When a Boss Pokémon is starting to smoke and shake before a big attack, when you hit it, it is more likely to wobble