COGEN: Sword of Rewind

COGEN: Sword of Rewind is a 2D action game inspired by Mega Man Zero combined with the rewind mechanic from Braid and starred by Unity Technologies Japan's Vocaloid mascot Kohaku Otori, also known as "Unity-chan", based on an animated short film from 2017.

Also, as part of a cross-promotion between Gemdrops and Inti Creates' Luminous Avenger iX 2, you can play as Copen in COGEN!

To do: Document the demo in the prototype page.

Unused Graphics#

ui_rank_d, ui_rank_e, ui_rank_f, and ui_rank_g

There would have been ranks even lower than a C but were scrapped before they finalized their graphics.

ui_talk_face_hugo_sp

One of Hugo's facial expressions, it's the only one without his eyepatch.

ui_talk_face_kohaku_B_close	ui_talk_face_kohaku_B_damage	ui_talk_face_kohaku_B_surprise	ui_talk_face_kohaku_B_disgust
ui_talk_face_yuko_close	ui_talk_face_yuko_damage	ui_talk_face_yuko_surprise	ui_talk_face_yuko_anger
ui_talk_face_misaki_close	ui_talk_face_misaki_damage	ui_talk_face_misaki_surprise	ui_talk_face_misaki_anger
ui_talk_face_mimori_smile

Additional faces for the characters in the true ending sequence go unused due their limited screentime. They could have been intended to have a larger role in the story based on their presence in The Phantom Knowledge short film.

Partially obscured#

All of the character portraits in the game are actually drawn in full body, the game cuts them off at bust height. This reveals certain details, like that Yuji Otori's casual portrait still holds an unfinished sword-like cane as it was simply drawn on top.

kohaku	kohaku_B	kohaku_c
exebraker	kiranahamrta
hugo	akaza	akaza_hologram
yuji	yuji_hologram	exe_yuji
mimori	yuko	misaki
acura

Regional Differences#

The game's title saw a very small change in Spanish-speaking territories as "COGEN" (despite of technically being pronounced as kˈɒɡən) could be misinterpreted as the third-person plural conjugation of the verb "coger", which is a vulgar slang for sexual intercourse in Latin American countries. To avoid confusion it was simply changed to "KOGEN" with a K. This change is reflected in both the game's logo, the script and even in store pages.

International	Spanish

Revisional Differences#

Ver. 1.01#

Released on February 3, 2022.

• Adjusted audio balance
• Fixed bug which prevented progress when loading in Windows 7
• Minor bug fixes

Ver. 1.02#

Released on March 18, 2022.

• Difficulty Added: Casual Mode
  • Jump limit: 2x > 3x
  • The rewind gauge charges much faster
  • You are invincible while dashing forward
  • Gain a barrier that nullifies 3 enemy attacks (Falling or getting crushed still kills you.)
  • Points earned (scoring) are reduced on the Results screen (Bonuses can still be earned, but points gained for Clear Time, Crushed Enemies, and Death Count are reduced to 0.)
  • You can now choose to skip the post-stage Results screen entirely (The Results screen will be disabled in Casual Mode by default, but can be toggled via the Options menu.)
• Difficulty Added: Hard Mode
  • Certain enemies and bosses move faster
  • Certain enemies and bosses attack faster
  • Enemies will take less time to fire bullets
  • Boss attacks have been powered up
  • The number of checkpoints has been reduced
• New Feature: Retry from Checkpoint
• New Feature: Suspend Game
• New Feature: Skip Results Screen
• Clarified Autosave Timing
• Tweaks to Actions
  • When Dash and Jump are pressed simultaneously, Dash will now take precedence
  • Changed the Crouch action to prevent accidental crouching while moving forward
  • Wall jump actions can be interrupted and canceled by pressing Attack after performing a wall jump*
  • Removed the windup animation before performing a wall jump*
    *Actions marked with a "*" can be toggled back to their original functionality via the Options menu.

Ver. 1.03#

Released on March 25, 2022.

• Fixed a bug where retrying at a specific point could make progress impossible
• Fixed various other bugs caused by retrying, such as one that caused constant, invisible attacks to trigger
• Minor bug fixes

Bug fix#

Released on October 3, 2025.

• Fixed security issues originating from the game engine.