Dr. Yùndòng

From Sonic Retro

Dr. Yùndòng
Version: Alpha
Last release: Dec 1st, 2019
System: Sega Mega Drive
ROM size: 2 MB
Original game: Sonic the Hedgehog 3 & Knuckles
Credits: BinBowie, Ralakimus, VAdaPEGA,
LuigiXHero, Natsumi, MrCat, LooneyDude, DragonWolfLeo, TheBlurCafe, Misinko, Brent Rigby

Dr. Yùndòng (DR.运动) was a very ambitious ROM hack project by Owarisoft that used Sonic the Hedgehog 3 & Knuckles's engine as a base with tons of original content. It has been cancelled as of October 2019 due to a development hell situation.


Dr. Yùndòng's development started in 2015 when a joke image created by BinBowie showing Sonic with a Caterkiller's face was sent in a private Skype group which was to become Owarisoft shortly after. Several people in the group absoultely loved this image, so much that the character was planned to be put in a Sonic ROM hack and was named "Lover The Catterhog".

Plans were made in a Google Docs document for the game, originally titled "Yùndòng Zìxíngchē" (运动自行车) as it was planned to be both the "Parodius of Sonic hacks" and a tribute to Chinese bootleg games, given the nonsense title. The hack started out simple at first before the team started throwing more and more ideas in as development followed.



Lover the Catterhog has the ability to attack by biting his enemies via the A Button and can climb up slopes when you hold the down button as you move forward.

Other tidbits

A total of 69 original audio tracks by BinBowie were composed specifically for this hack. Other crowning achievements that were achieved were that a 32x32 chunk system was implemented into the game, as opposed to the 128x128/256x256 chunk systems the classic Sonic games used, which allows much more creativity with the level design, a completely custom overworld, a special stage modeled after the classic 1984 Sega arcade game Flicky, and a fully implemented inventory system complete with various shops you can buy and sell objects from.

Planned features that never made it to the game include sidemissions you could both complete in the individual platformer levels and overworld, hats for the main character that would effect the game in multiple ways depending on what hat the character was wearing, multiple different endings and even a hidden level only accessible when meeting certain conditions.

There were also plans of getting a demo of this hack into the 2016 Sonic Hacking Contest but plans fell through due to extreme crunch time being needed for this to go through.


  • Project Leader - BinBowie
  • Lead Programmer - Ralakimus
  • Engine Programmers - Ralakimus, Natsumi
  • Assistant Programmers - Natsumi, TheStoneBanana
  • Level Designers - LuigiXHero, BinBowie, LooneyDude
  • Level Artists - BinBowie, VAdaPEGA, TheStoneBanana, Mr. Cat, LooneyDude
  • Sprite Artists - BinBowie, VAdaPEGA, TheStoneBanana, LooneyDude
  • Music Composer - BinBowie
  • Sound Effects - VAdaPEGA
  • Character Designers - BinBowie, VAdaPEGA, Ralakimus, TheBlurCafe, TheStoneBanana, Dragon Wolf Leo
  • Dialogue - Misinko, BinBowie, Brent Rigby
  • Dual PCM and AMPS - MarkeyJester and Natsumi


Download.svg Download Dr. Yùndòng
File: yundongfinalbuild.7z (472 kB) (info)

Note: This is an extremely unfinished build and the game isn't planned to be worked on ever again. Some stuff may appear broken. To access the main stages go to the "Level Select" which is available on the main menu.

External links