Viridian Ending

Viridian Ending is the 36th level in Pokemon Tower Defense. However, it is only a movie level requiring none of your Pokémon to be used.

Description
After having defeated Gary and Groudon, you regroup with your allies in Viridian City. A freed Gary presents you with the Earth Badge, three new HMs (Fly, Surf, and Strength), as well as the Max Potion. Just as you are about to head off to the Indigo Plateau to confront Mewthree, Brock shows up with Jessie and James in tow, similarly freed from mind-control. After they proclaim that Mewthree's minions have blocked off the Indigo Plateau, Gary plans to create a diversion and allow you to sneak through.

After everybody else leaves, the Old Man stays behind to speak with you; he suggests exploring a bit using your new HMs before heading off to Mewthree.