A History of Revolutionary Shoot-'Em-Ups

Hey Team, I wanna play every revolutionary shoot-'em-up, in order of release, so that I can get a first hand impression of how the genre has progressed. "Revolutionary" can be defined however you like. This is the list I've come up with so far. Any thoughts? Any glaring omissions? Any games on the list that shouldn't be?

Spacewar!

Space Invaders

Asteroids

Defender

Galaga

Xevious

Thunder Force

1942

Gradius

TwinBee

Darius

Life Force (also known as Salamander)

R-Type

Axelay

Gunbird

Battle Garegga

DoDonPachi

Radiant Silvergun

Giga Wing

Ikaruga

Espgaluda

Gradius V

Mushihimesama

Deathsmiles

Jamestown: Legend of the Lost Colony

Crimzon Clover

Sine Mora

Astebreed

Rigid Force Redux

Rolling Gunner

ZeroRanger

Sisters Royale

UPDATE (4 days after the original post):

Thanks to all the comments in this thread, this is the updated list, expanding the original 32 games to a whopping 72 (which may not even be enough!), in chronological order.

Before browsing, I want to acknowledge that I know some of these, particularly the games after Ikaruga, are highly debtable! But this is the compiled list from your suggestions, of revolutionary shoot-'em-up games.

For the record, for me, revolutionary means bringing something new to the table, OR, using something from the past, but to a level of perfection not yet seen at that point in gaming history. But perhaps it means something different for YOU. :D

Spacewar!

Space Invaders

Asteroids

Defender

Galaga

Bosconian

Scramble

Xevious

Time Pilot

River Raid

Yars Revenge

Thunder Force

Super Spy Hunter

1942

Gradius

TwinBee

Tiger-Heli

Space Harrier

Gun Frontier

Darius

Life Force (also known as Salamander)

Side Arms

Zanac

R-Type

Twin cobra aka Kyokyoku tiger

Hishouzame (known as Flying Shark in Europe and Sky Shark in North America)

Parodius (specifically Parodius: The Octopus Saves the Earth, also known as Parodius: Tako wa Chikyū o Sukū in Japan)

Blazing Lazers (known as Gunhed in Japan)

Omega Fighter

Raiden

GG Aleste

Summer Carnival '92: Recca

Boogie Wings

Viewpoint

Gleylancer

Raiden II

Batsugun

V-V (also known as "V-Five" or "Grind Stormer" in some regions)

Cybattler

RayForce (also known as Layer Section in Japan, Galactic Attack in North America, and Gunlock in Europe)

Shippuu Mahou Daisakusen

DonPachi

Tyrian

Cho Ren Sha 68k

Battle Garegga

Twinkle Star Sprites

DoDonPachi

Dodonpachi

Touhou

Einhander

Radiant Silvergun

Giga Wing

Psyvariar

Ikaruga

Progear

Shikigami no Shiro

Touhou Koumakyou: The Embodiment of Scarlet Devil (commonly referred to as Touhou 6)

Ketsui

Jets'n'Guns

Judgement Silversword

Radirgy

Sky Force Reloaded

Hellsinker

Genetos

Illvelo

∀kashicverse

DonDonPachi Maximum

Aka To Blue

ZeroRanger

Ginga Force

Angel at Dusk

CYGNI