It sounds like you're looking for information about — likely the browser-based flash game Zombotron from the early 2010s, with "hacked" referring to a modded version featuring cheats (e.g., infinite health, ammo, money, or all weapons unlocked).
Allowing users to manually freeze their health and ammo values. zombotron hacked
But for the classic "hacked" instant-gratification version, search for: It sounds like you're looking for information about
October 26, 2023 Subject: Security Risks, Gameplay Implications, and Safety Concerns regarding "Hacked" versions of the Zombotron game series. search for: October 26