Games like ionAXXIA
Games like ionAXXIA include Nova Drift, Bit Blaster XL, DoDonPachi Resurrection, Cyberhunt, and SNKRX. We matched them by the tags players give ionAXXIA on Steam (Space, Shoot 'Em Up, Souls-like, 1990's, and Top-Down Shooter): closest matches first, and among equally close ones the better-known games.
Nova Drift
Shared: Shoot 'Em Up · Arena Shooter · Arcade
Bit Blaster XL
Shared: Shoot 'Em Up · Shooter · Arcade
DoDonPachi Resurrection
Shared: Shoot 'Em Up · Top-Down Shooter · Shooter
Cyberhunt
Shared: Shoot 'Em Up · Space · Indie
SNKRX
Shared: Shoot 'Em Up · Top-Down Shooter · Arena Shooter
Star Saviors
Shared: Shoot 'Em Up · Space · Arcade
FTL: Faster Than Light
Shared: Space · Sci-fi · Indie
Chippy
Shared: Shoot 'Em Up · Top-Down Shooter · Arena Shooter
STAR WARS™ Battlefront™ II
Shared: Space · Shooter · Sci-fi
Heat Signature
Shared: Space · Sci-fi · Indie
Sky Force Reloaded
Shared: Shoot 'Em Up · Top-Down Shooter · Arcade
Halo: Spartan Assault
Shared: Top-Down Shooter · Sci-fi · Shooter
BALL x PIT
Shared: Shoot 'Em Up · Top-Down Shooter · Arcade
Ikaruga
Shared: Shoot 'Em Up · Arcade · Sci-fi
ESCHATOS
Shared: Shoot 'Em Up · Top-Down Shooter · Shooter
ZeroRanger
Shared: Shoot 'Em Up · Indie · Arcade
STAR WARS™ Battlefront II (Classic, 2005)
Shared: Space · Shooter · Sci-fi
Starblast
Shared: Space · Shoot 'Em Up · Arcade
Planes, Bullets and Vodka
Shared: Shoot 'Em Up · Shooter · Arcade
Shotgun Witch
Shared: Shoot 'Em Up · Top-Down Shooter · Arena Shooter
STAR WARS Jedi: Survivor™
Shared: Souls-like · Space · Sci-fi
Half-Life
Shared: 1990's · Sci-fi · Shooter
STAR WARS™ Republic Commando™
Shared: Tactical · Sci-fi · Space
HELLDIVERS™ 2
Shared: Space · Shooter · Sci-fi