A beautiful mess.
Link to the mod:
https://www.moddb.com/mods/hl2-overcharged
Songs:
Fork in the wall (NMH)
Klaymen Shuffle (neverhood)
N. Sanity Island (crash twinsanity)
Level Editor Music 1 (Battle block)
Main Menu Theme (Battle block)
Dynamite Fishing (Max and the Magic Marker)
Comet Observatory
Cup Head songs I cannot name without youtube flagging this video