Vacant Ark

Vacant Ark is a dark and atmospheric indie Bullet Hell Shoot'Em Up developed by Buster, available as the third game here. It takes a bit of inspiration from the R-Type series but is quite novel in itself. Ammunition is required for any attack besides a weak close-range attack, but you can get this ammunition by blocking enemy bullets with something akin to R-Type's force device.

An oceanic planet is discovered. Scientists on Earth create a cyborg mermaid and have a little girl remotely pilot it, in order to explore the planet. It turns out that a good deal of the life in the ocean is hostile.

Vacant Ark contains examples of the following:

 * Bullet Catch: A critical part of the gameplay.
 * Bullet Hell
 * Downer Ending:
 * Duel Boss: The red-haired mermaid also has a force device, and uses red crystals for ammunition.
 * Easy Mode Mockery: The Shallow game ends after the first stage.
 * Evil Counterpart: The red-haired mermaid
 * Fetus Terrible: Embryos/fetuses are recurring enemies.
 * Idiosyncratic Difficulty Levels: Shallow, Middle, Deep and Abyss.
 * Nintendo Hard
 * Recurring Boss: The red-haired mermaid, although she usually has another boss in front of her until the final stage.
 * Shout-Out: One of the music tracks is named "Zunchacha" for a major Taito music composer, Zuntata
 * Timed Mission: Some of the bosses will leave if you take too long to defeat them.