Geometry Wars

Shoot Em Up series, similar to Robotron2084, where you control a claw-shaped concave octagon in a quest to destroy many other shapes. Primarily notable for reinvigorating the stale genre and for having insane amounts of stuff on the screen at once (due to the minimal computational power required for each object). Originally an Easter Egg in the Project Gotham Racing series for the Xbox. The series' second incarnation Geometry Wars: Retro Evolved and its sequel have been released as stand-alone games for the Xbox360 Arcade. It also has a DS and Wii version Geometry Wars: Galaxies, as well as a PC clone (with more features) called Grid Wars, whose development was reportedly stopped at the request of the parent company. It seems this was sorted out, as Grid Wars 2 can be downloaded for free. Geometry Wars: Retro Evolved is also available for the PC via Steam.

This series provides examples of:
 * 1-Up
 * Asteroids Monster: Purple squares.
 * Attack Drone
 * Cap: The highest composite score obtainable on Galaxies is [(2^30)-1]x25.
 * The DS version also has some unfortunate (or maybe fortunate) limits to onscreen objects.
 * Collision Damage
 * Embedded Precursor: Galaxies contains a full copy of Retro Evolved.
 * Endless Game
 * Every Five Thousand Geoms
 * Everything Trying to Kill You
 * Exactly What It Says on the Tin
 * Game Level
 * Level Grinding: In Galaxies, you have to level up your drones by playing stages.
 * Mercy Invincibility
 * Money for Nothing: You'll unlock everything in Galaxies long before you receive all the bonus geoms for hitting score plateaus.
 * Mook Maker
 * No Plot, No Problem: You are a claw-shaped object inserted into the game grid. Other simple geometric shapes are generated, and they try to destroy you. What would need more for?
 * One Game for the Price of Two: The DS and Wii versions of Galaxies unlock content on each other (the same content on both), but are otherwise identical.
 * Also inverted in that Geometry Wars started out as a game inside Project Gotham Racing, and has since had some form in its games. Geometry Wars: Retro Evolved in Project Gotham Racing 2, Geometry Wars: Retro Evolved in Project Gotham Racing 3, and Geometry Wars: Waves in Project Gotham Racing 4. Two games for the price of one.
 * One-Hit-Point Wonder: The protagonist in all games. However, you can get extra lives through an 1-Up equivalent.
 * Even more so in Galaxies's "Sur-" (Survival) stages, where you get one life, no bombs, and no way to get more of either.
 * Pacifist Run: Exactly What It Says on the Tin for the "Pacifism" mode in Geometry Wars 2.
 * Pinball Scoring: The "Min-" levels in Galaxies. Using the mines in conjunction with a maxed-out (x150) score multiplier, a Mook Maker, and the harmless bonus-point golden UFOs will allow you to rack up hundreds of millions in points within seconds. Heck, on the earlier "Min-" stages, you can go from below Bronze to exceeding the requirement for a Gold medal in the span of less than three seconds.
 * Repurposed Pop Song: Galaxies uses "Particle Man" here.
 * Respawning Enemies
 * Scoring Points: The point of Retro Evolved and Retro Evolved 2, and what you need to do to advance in Galaxies.
 * Segmented Serpent: The worm enemies, which can only be attacked in the head.
 * Shoot Em Ups
 * Shout-Out: The "Wax On" and "Wax Off" Achievements.
 * Smart Bomb
 * Tele Frag
 * The Tetris Effect: Given the simple designs of the enemies, it's not too far-fetched to suddenly imagine shapes around you to start moving in Geometry Wars patterns.
 * Theme Naming: Levels in Galaxies follow a strict format: three letters for the type, then something denoting a cardinality (e.g. MinDuo is Mine level 2).