Zombie Hunter, which was once slated to be released in the US as Zombie Master, is a scrolling hack and slash adventure. It's like Zelda II in a way, except Link has a shield that he can actually use, instead of just adding to his total defense rating like in Zombie Hunter. Having a functional shield would've made this game a LOT more tolerable, I imagine. Anyways you walk to the right and slash at various foes that appear. Eventually you get enough experience to level up, and you also get gold sometimes, and items even less of the time. Like, you can get Food that (thank God) restores your HP, or maybe you'll get more powerful weapons or equipment, or maybe the key that unlocks the last door that lets you finish the level. The enemies don't seem to do any damage by themselves (you can jump on them for much amusement), but they can all fire projectiles that hurt quite a bit. Why your shield is, again, useless for deflecting projectiles, is just a bit annoying.

This patch is an improvement over another bug fix patch, originally released by KingMike's translations (https://www.romhacking.net/hacks/39/).
The original aimed to keep stat modifiers provided by equipment on level up, but the modifications broke level progression after level 7, and also kept equipment stats in a weird way, where energy buffs weren't kept while defence could be lower than expected in some cases.
This version keeps equipment boosts of both defence and energy and lets you level up after 7. Like the original patch, this patch was made on the original Japanese ROM, but it should work on the translation.

Database match: Zombie Hunter (Japan)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: 087BCE6F9D3BE307B973CE050681CEFA9D97449D
File CRC32: CC5A32D5
ROM SHA-1: 0D528F7DFA126CCF9BF4B943787ACD054B858313
ROM CRC32: 41632CB6