The archetypical bullet hell shooter think Ikaruga or TwinBee are top-down, two-dimensional aerial battlefields locked on an infinite vertical scroll. One daring spaceship or fighter jet must evade a wild morass of spherical, slow-moving projectiles, while destroying an armada of puny, fragile interceptors. In that sense, Luna Abyss deviates from the established tradition in some fascinating ways. This is a first-person shooter that cribs liberally from the quarter-eating cabinets of yore; your field of view billows up with floating bullets, but unlike Halo or Call of Duty, you’re not expected to duck behind cover in order to survive. Instead, in Luna Abyss, players will be squeezing through the slight crevices in between the shells in the same way you might slip through the empty space in an Enter The Gungeon shotgun blast. It’s a wild idea, and after a brief demo, there’s a chance Luna Abyss sticks the landing.
Source: N4G PC Luna Abyss Is a Movement-First Bullet-Hell FPS Set in a Space Prison – IGN