Drains GBC is a simple enough homebrew Game Boy Colour game developed by JPM.
Your aim is to sweep clean the whole drain system before this crawling plague gets out of control.
The city drains are well known hideouts for vicious and bizarre creatures of the underworld.
Some of the rooms have been locked for ages. You will have to find the right key to gain access and fight the creepy creatures awaiting inside. Once you’ve finished them all you’ll be rewarded with something useful that will help you on your quest.