MINUS ZERO

Minus zero is a very simple game with minimal controls and simple presentation. You control a small triangle that is put up against an onslaught of bullets with only one live. One kill you're dead, restart. The great thing about this game is the mechanics: any time you shoot, or while your shots connect, you will be invincible for a short while, indicated by your triangle turning red. In order to give you enough invincibility time, you can not only lock onto enemies, but also bullets. The game quickly ramps up its difficulty very quickly, so it's not for the easily angered.
Beware though: options are extremely limited: no key rebinds (360 controller is supported), no fullscreen option (only 1:1 scale and a 1.5x increase of that resolution). The only things you can do is change the screen size between two settings and switching the language between Japanese and English.

Fun quick little game. But I only recomend it if you wish to complete your Triangle Service collection : aside the nice gimmick, it's not nearly as polished as the rest.
Not that it's a bad game by any mean, but consider it if you've got money to waste. It will always be a better investement than buying a drink!

Minus Zero was originally released in 2009 for Xbox 360 as part of the "Shooting Love 200X" collection, which brought together beyond this game other three: "Shmups Skill Test", "Trizeal Remix" and "Exzeal", all of them developed by Triangle Service (japanese developer founded by a former employee of Konami) and now in 2016 this game finally comes to Steam at the hands of Degica, publisher that has been noted for bring to the Steam (and thus to the whole world) many shmups (acronym for shoot' em up aka STG) previously restricted only to Japan. Minus Zero is a minimalist shmup in essence and unique in what it claims to do: be a shmup based solely on "Lock on", in which enemy targets are previously locked through of a cursor and then, by pressing a single button, homing missiles will hunt down and destroy the marked targets. During the explosions of enemies, the screen flickers and during this period of flicker the ship of the player (in the shape of a triangle) becomes invincible (that is visually confirmed when the ship turns red). There are several stages and the pattern of movement of enemies will become increasingly complex. The points of the yellow enemies come to increase over time (the current value is displayed the bottom of the screen), then the longer the player to wait before shooting more points will tend to accumulate. Due to its deliberately minimalist features, menus, graphics, sounds and game controls are extremely simple and direct. About the controls you'll use only the digital pad or analog stick to move the ship and a single button to shoot the homing missiles, nothing else. The gameplay is intense and the level of difficulty is progressive. You can save replays of matches and the game also has an online leaderboard very good where you can watch the replay of other players inside the leaderboard, something always useful for those who want to know and learn the patterns and techniques used by the best players. Unfortunately, the game still doesn't have a full screen mode available, so I was forced to play in windowed mode, even using the Steam Big Picture, but perhaps its possible that this mode can be added to the game in some future update. Minus Zero is different from all the shmups I have ever experienced, with its unique features provide an interesting, intense and fun experience. Below two videos of this game played by me:

I found this game very enjoyable, though it has many limitations.
Full review:
It's too long, so Steam won't let me post it. :/
Short version:
Control your little triangle. Lock onto targets while dodging. Fire at them and become invincible as they explode. Repeat. Repeat. Shoot the red circle to go to the next level. Repeat.
Score points. Climb the leaderboard. Have one more go.
There is 360 controller support. There is keyboard too but you can't remap the keys. You can't go full screen. There are next to no display options. There's no story mode. No cutscenes. Barely music and backgrounds. But it's fun and worth playing.

I have played this much more than I would like to admit for how bad I am at this game. I have played several shmups, but not really any with lock-on shooting (the only one that comes to mind is some of the DLC in DariusBurst Chronicles Saviors). This game is very simple: lock onto enemies and bullets, shoot, watch them explode. As you watch them explode, you are invincible, which is the key to survival in this game. This becomes surprisingly addictive and I always find myself pressing A to start a new game even after I told myself that my last run would be my last for the day. There are no options, setting, cut scenes, ship select, or text to go through when starting a game...you are in the action immediately so this is a great game to play for only a few minutes (though you may end up playing for much longer, like I do).

Great game!
-Reduce 'splosion fx so player tracking is viable
+The leaderboard and replay systems are great and should be in every score attack game