Thunder Castle is an action maze game that was developed by the Intellivision Corporation for their video game console the Intellivision. It later received an unlicensed port of sorts to NES hardware through their Intellivision 25 Video Game System, a game system filled with Intellivision classics in a plug-n-play controller that runs on NES hardware. Like the original version, the game is simple: you control a knight going through a maze filled with enemies, and your objective is to destroy the biggest threat in each maze, whether they are dragons or sorcerers. Some of them can only be killed when the knight is energized, which in this game is done by picking up a special grail.

Winslinator plays this very obscure port of an Intellivision original and manipulates the game's RNG into giving them the most ideal layouts and item drops in order to beat the game as fast as possible.