Satisfying Unique Secrets

[GibblyJones]

What are some map/gameplay mods that add satisfying secrets? I don't care for orbs, I don't like how they limit the colors. I'm looking for something that has unique pick ups, interesting lore or unique aesthetic secrets, like a room with a video playing, some sort of interactive gimmick or music that you can just hang out in and take a break for a while. If it's a vanilla map I always play with roguelike arsenal so secrets are rewarding with loot boxes, but i'm looking for something that has unique secrets built in as a feature. Maps emphasized over gameplay mods that enhance secrets, both are fine though.