Petro-Plus

Petro+, pronounced Petro-Plus (ペトロプラス), is a 2D action-adventure game developed and published by Namco exclusive for the WiiWare. Produced in commemoration of the Petropolis series' 15th anniversary, the story follows Thunder and his companions as they venture to defeat the "Giant Islanders," who arrived on the Petro Islands in search of their resources. The game homages the original classic games, featuring fast-paced action gameplay.

Story
Set to take place after Petropolis 4, the beastmen of Petro Islands are visited by five "Giant Islanders" (a term beastmen use to describe humans). Leading them is the emotionless Karlos, who orders the other four to build machines on most of the islands in order to obtain their resources. Witnessing this, Thunder informs three of his friends about what he saw and joined him on their new adventure to defeat the Giant Islanders.

Playable

 * Thunder Storminski
 * Selene Melodia
 * Milton Redder
 * Spike Sparks

Non-Playable

 * Jessica Magnets: A strict yet beautiful businesswoman in charge of her father's electrical company. She now resides in the Southwestern Islands.
 * Abel Crones: A professional sniper who was once reported MIA during a war on one of the Giant Islands. He is now located in the Northern Glaciers.
 * Marsha Price: An innocent princess who is about to rule a kingdom from her Giant Island home. However, she choses to control the Eastern Islands.
 * Thomson Higgins: An intelligent yet inept professor who plans to make a change in his life. To start, he choses to stay in the Azure Islands.
 * Karlos: A human who is the enigmatic leader of the Giant Islanders invading, as well as the main antagonist. Despite his brilliance at a young age, his parents gave him little attention and he spent most of his childhood alone. In his adult years he became embittered and after feeling nothing but sadness and anger during his youth he decided to create a world of nothingness, starting with the Petro Islands. He resides on the Central Islands.