Iwanaga

Iwanaga is an indie Bullet Hell Shoot Em Up developed by Buster, available as the second game here. Its gameplay is usually described as a combination of Alien Soldier and Sin and Punishment with a healthy dose of Bullet Hell. Each difficulty level is effectively a different game, or at the very least, has different bosses and stages in some parts while being of roughly equivalent length. A playthrough of the Hard route by mrmonkeymans is viewable here.

Long ago, there were two lineages from a goddess: one of flower, and one of rock. The children of rock called themselves the Old Order and tried to exert control. During the Showa Era, such stories were lost to myth, until a village was discovered with some interesting tales to tell. In particular, there were stories about a conflict near the location of a modern dam. This game shows what might have happened long ago...

A 3-D remake named Another Iwanaga is being released in 2012, this time being a mix of Sin and Punishment and Ikaruga.

Iwanaga contains examples of:

 * BFS: Wielded by one of the bosses.
 * Boss Game: True to its Treasure influences, the game is basically a series of boss fights interspersed by chances to regain health and time.
 * Breather Level: Almost all of the parts consisting of numerous weak enemies, so that the player can refill on health and time.
 * Bullet Hell
 * Cyborg: The main character appears to be this, complete with autocannons for arms.
 * Downer Ending:
 * Eldritch Abomination: Many of the Old Order members can be interpreted as this.
 * Everythings Worse With Bees: Big demonic bees, no less.
 * Fusion Dance: How the game starts; as the hero begins his transfiguration into the guardian, his sister phases into him, apparently as a guiding spirit.
 * Guardian Entity:
 * Human Sacrifice:
 * Miko: One is involved in the Easy ending.
 * Shrouded in Myth: The backstory of the game. The substrate is a myth about the origins of humanity from Ninigi no Mikoto; because he chose the (beautiful) flower-princess Konohanasakuya, rather than the (ugly) stone princess Iwanaga, humans' lifespans are fleeting like flower blossoms, not eternal and enduring like stone (they were both daughters of the mountain lord Ohoyama). Although looking at some of the horrors that are Old Order members, Ninigi may have made the right decision anyway...
 * Timed Mission: A crucial part of the gameplay.
 * Turtle Power: One of the bosses is a big stone turtle who sometimes exposes its heart.
 * Youkai: Goes with the whole feudal Japan theme.