As requested by Chunky, here's a list of ALL the PC Engine shooters i could think of. There may be one or two missing, if so, let me know! In parenthesis are things you need to know, translations of titles if I have em, prices of the rarer games, and US titles of some games! And without further ado:
1943 Kai
Aeroblasters
Ai Cho Aniki (Super Big Brother)
Alzadick Summer Carnival
Armed F
Atomic Robo Kid Special
Avenger
Barunba
Bouken Danshaken Don San-Heart Hen (Lost Sunheart)
Burning Angel
CD PC Denjin Rockabilly (Super Air Zonk)
Cho Aniki (Big Brother)
Coryoon
Cotton
Cybercore
Daisenpu
Daisenpu Custom
Darius Alpha ($1000 easy!)
Darius Plus
Dead Moon
Deep Blue
Detana! Twin Bee
Double Ring (W Ring)
Download
Download 2
Dragon Saber
Dragon Spirit
Final Blaster
Final Soldier
Final Solider SE (VERY rare LE time attack...over $200)
Galaga '88 (Galaga '90)
Gate of Thunder (Gates of Thunder)
Ginka Fukei Densetsu Sapphire (Sapphire....$300ish)
God Panic
Gradius
Gradius II: Gofer
Gunhed (Blazing Lasers)
Gunhed SE (VERY rare LE time attack...over $200)
Hani in the Sky
Hawk F-123
Hellfire S
Image Fight
Image Fight 2: Operation Deep Striker
Kiaden 00
Kyuukyoku Tiger
L-Dis
Legion
Macross 2036
Magical Chase (over $100 easy)
Metamor Jupiter
Mr. Heli
Monster Lair
Nexzr
Ordyne
Override
P-47
Paranoia (Psychosis)
Parodius
Power Gate
Psychic Storm
Psycho Chaser
PC Denjin (Air Zonk)
Rabio Lepus Special
Raiden
Rayxanber II
Rayxanber III
Rock On
R-Type (US one has R-Type 1 and 2 on one card)
R-Type 2
R-Type Complete
Salamander
Side Arms - Hypedyne (Sidearms)
Sidearms Special
Soldier Blade
Soldier Blade SE (VERY rare LE time attack...over $200)
Space Invaders
Space Invaders: Fukkatsu No Hi (Space Invaders: Rebirth)
Spriggan
Spriggan Mark 2
Star Paroja
Steam Hearts ($150+)
Summer Carnival '93: Nexzr Special
Super Darius
Super Darius 2
Super Raiden
Super Star Soldier
Sylphia ($100+)
Tatsujin
Saint Dragon
Terra Cresta 2
Terraforming (Syd Mead's Terraforming)
Thunderblade
Toilet Kids
Toy Shop Boys
Winds of Thunder (Lords of Thunder)
Xevious
Zero Wing