Now and then I've tried making comments to the disassembly of this game. I wanted it to be more complete before uploading it, but for now I've lost interest in the project and decided to go ahead and upload it as is. I hope someone finds it useful.
To me the mountain in the background of this game looks wrong. If you set MOUNTAIN_FIX to 1, it looks better in my opinion.
I've always thought it strange that this game has a timer, but nothing happens when the timer reaches zero. You can change the value of TIMEOUT to change what the timer does. In order to get some free ROM to make these changes, I removed a couple NOPs that are near STA WSYNC. I hope this doesn't cause any problems. Despite me having a Harmony cart, I don't remember testing these changes on real hardware.
I did have options for a couple things that I removed from this copy. Since they came from someone else's code, I didn't want to use them without permission. With other things going on in my life, I may not be on here much/any in the near future and wanted to go ahead and post this.
This download is just a zipped ASM file.
Dangerous_Mouse_Hunt_(Gefaehrliche_Maeusejagd_hack)_2013y08m15d_05h09m.zip