Hunt Down the Freeman (HDTF) is famous in the gaming community, but mostly for being one of the most poorly received Half-Life fan projects ever released. If you are playing the 2022 version, you are likely seeing the "Post-Fix" era where some of the game-breaking bugs were addressed.
A very different tone than the silent-protagonist style of Valve’s games.
If you get stuck, look for vents or glowing prompts. Level design is notoriously confusing, and sometimes the "next step" isn't triggered unless you stand in a very specific spot. Technical Tips for this Release
Because it uses an emulator, your save games might be stored in a different folder than the official version (usually inside the game folder under a settings or saves directory). A Guide to the Game: "So Bad It's Good"
Unlike traditional "cracks" that modify the game's .exe file, this usually just replaces the steam_api(64).dll file. It tricks the game into thinking you are logged into a legitimate Steam account.
Antivirus software often flags steam_api64.dll as a threat because it’s a "crack." You will likely need to whitelist the game folder to keep the file from being deleted.
The AI can be erratic. Use the "lean" mechanic to peek around corners, as enemies often have pinpoint accuracy at long ranges.