ShadowMario/FNF-PsychEngine ? reverse-engineered prompt

Build me a Friday Night Funkin style game engine that fixes a lot of the vanilla issues but still feels easy to use for making mods.

I want the game to have a polished main menu, story mode, freeplay, settings, achievements, credits, and a mod manager where players can turn mods on and off. It should support custom scripting for songs, events, and gameplay tweaks without needing to dig into the core source every time. Add a chart editor with support for event notes, note types, decimal BPM, and easy adjustments for timing and note behavior. I also want multiple built in editors to help with mod creation, plus options for things like downscroll, middlescroll, note colors, framerate, flashing lights, and combo behavior.

Make it feel modern and mod friendly, with animated dialogue, nicer menus, and a lot of the rough edges cleaned up. If you need to check current docs or examples, look them up online.