Touhou Doumeiju: Mystical Power Plant

Touhou fangame by Kaisendo. The main gameplay mechanic of Mystical Power Plant is based around collecting leaf items to fill a gauge, which causes the player to 'level up' and gain various benefits as the game proceeds. The benefits vary depending on what character duo is chosen.

Written by Milka Oyasu, the story centers around a giant tree that Kanako Yasaka has brought to the Youkai Mountain from the Outside World. She intended for said tree to serve as a symbol of Gensokyo's newfound age of ecology, and it was called the "Life-Guiding Tree" to reflect this.