TWilight INSanity

TWilight INSanity is a bullet hell shoot-em-up made by AQLOOP, and was released on May 9th, 2006 It is a story-focused game with numerous dialog choices, branching paths, and endings.

History

At some point after the release, the v2.00 patch introduced the Sequel Stage.
In 2013, english patch was released by Seiha Translations.

Story

Introductory backstory, from the game's prologue:
Near the end of the 21st century, the human race created a computerized virtual world called Ill-net (Illusion Network). It was restricted only to researchers at first, but later opened to the public and eventually became commonplace. Additionally, development of artificial intelligences greatly advanced in this virtual world. Artificial Human Circuits (AHCs) allowed AIs to think and feel just like real humans. The Artificial Humanoids (AHs) using the AHCs act as guides and protectors for the residents of Ill-net.

Characters

You get to choose to play as one of three pairs of twins, all of which have different shot types and stats.

Haneita Twins

Name	Shot Type	Shot Power	Move Speed
Shinya Haneita	Straight	7	7
Sakura Haneita	Wide	5	5

Saijou Twins

Name	Shot Type	Shot Power	Move Speed
Yuuri Saijou	Line Laser	11	11
Mayuu Saijou	Wide & Guided	1	9

Hoshimi Twins

Name	Shot Type	Shot Power	Move Speed
Maiha Hoshimi	Straight±30°	9	3
Tsubasa Hoshimi	Wide	5	1

Gameplay Overview

The game features 3 difficulty modes: Easy, Normal and Hard.
It's a rather difficult game in general though, even on Easy.

Controls

The controls in this game can be very confusing, but i tried my best to make sense of them.
The following lists the default controls. They can be changed in the Config menu.
There may also be a KeyConfig.exe in later versions, which has more options particularly for Keyboard.

Keyboard	Switch Pro Controller	Effect(s)	Notes
Arrow Keys	Left Joystick	Move Character, Navigate (Menu)
Enter, Y	B	Focus + Shoot, Advance Dialog, Confirm (Menu)	yeah this is a weird quirk this game has, you cannot focus without shooting
Spacebar	L	Shoot
X	A	Tension
C	Y	Switch Character
X	ZR	Cancel / Back (Menu)	*only in main menu
Shift	R	Fast-forward Dialog, Confirm (Pause Menu)	*this Confirm button only applies in the pause menu
Esc	ZR	Pause / Unpause

For controller players, you can use SteamInput (if you have Steam installed, that is) to remap the controls for joystick.
I recommend binding the joystick inputs to the d-pad, it feels way better.

This game has the vectoring issue, meaning you go faster when moving diagonally.
When you start focusing, it takes a second for your character to actually slow down.

Mechanics

Buzz - it's like Graze in Touhou games. Getting close to a bullet will make the counter go up by 1.
Life - your lives. if you run out, you are asked if you wish to continue. I don't think continues are limited in any way, but using one will probably get you a bad ending.
E-Crystal - ???
Tension - Unleashes an extra-strong attack, destroys all bullets on the screen, vacuums items, and makes you temporarily invincible.
Auto-Tension - The game will automatically use a Tension when you get hit, should you have one. This will raise P-Rate quite a bit however.
TwinsRate: A bar that tilts to either left or right, depending on how much time you spend playing as the respective twin. This will affect certain dialog choices.

P-Rate

P-Rate (also called Erosion Rate) is very important, as it has decisive effects on dialog choices, and therefore the routes you have access to.
The lower your P-Rate the better, so try your best to keep it as low as possible.
Also, if P-Rate ever hits 100%, it's an instant Game Over.

Things that raise P-Rate:
-Losing a life
-Auto-Tension
-Any on-screen enemies will perpetually raise your P-Rate just by existing.

Things that lower P-Rate:
-Killing enemies. The faster you defeat enemies, the more it will lower the P-Rate. How fast you defeated them is indicated by a number that appears on their position (e.g. "X2"). This goes up to a maximum of X4(?), which is the best result.

Items

E-Crystal - Decreases P-Rate.
E-Crystals are dropped by defeated enemies (the faster you defeat them, the more you get).
When erasing bullets using a Tension, each will turn into E-Crystals.

S-Crystal (green hexagon with "S" in middle) - Increases score. Dropped by defeated enemies.

1UP - Gives +1 Life.

X-Crystal - Increases P-Rate.

Music

Main article: TWilight INSanity/Music
The soundtrack for this game was composed entirely by Yasetsu Kazamine.

Known Bugs & Glitches

When the game window becomes unfocused while in the pause menu or continues prompt, the game will permanently freeze. *This does not happen when in dialog, even when in the dialog choice UI.

Links

Endings Guide by Kiutgh2: https://www.reddit.com/r/shmups/comments/1myvijb/twilight_insanity_endings_guide/
English Patch version download link can be found in the comments section here: https://www.youtube.com/watch?v=-XbFnjIrsOo
Official Website (on the Internet Archive): https://web.archive.org/web/20070524042556/http://blue.sakura.ne.jp/~loop/twins.html