Jev Plays Manic Miner

In my last post Claude and I failed to get reinforcement learning to play Manic Miner, and we ended up solving the whole game with plain old search. Around the same time, TypeSafe released Jev. Jev is what they call a “System One” model - the name comes from the fast, instinctive kind of thinking, as opposed to slow, deliberate reasoning. It doesn’t generate text, it makes decisions. You give it some information about the situation (as JSON), a paragraph of instructions, and a list of options, and it tells you how likely it thinks each option is to be the right one. It’s fast (around 270ms per decision for me) and cheap - a complete attempt at a cavern costs about half a cent. Jev has already been used to play plenty of games. TypeSafe’s launch demos had it playing Doom from structured game state, and playing Wikiracing (get from one Wikipedia page to another using only links). People have since built Minecraft, Subway Surfers and driving demos, and there’s a Minecraft speedrun agent…