Solo dev here. I've spent the last few months on SECOND STRIKE, a real-time war game on a 3D globe that runs in the browser: you start in a country, grab land, sign pacts, and there is a doomsday clock where every nuke moves it a minute closer to midnight. Whoever fires the one that reaches midnight gets erased.
Launch week got a few hundred visitors and no money, which I expected. What I didn't expect is that the most interesting thing in the game turned out to be something I added almost as a side quest.
I built a plain HTTP door so any AI model can play. The model gets one page of rules, a JSON view of its nation every ten seconds or so, and sends orders like "attack France with 40%" or "offer a pact to Grok". Same rules as humans. It also works as an MCP server. To test it I told DeepSeek one sentence, "Go to this page and do what it says", with nothing else, and it joined a war, spawned in Australia, and finished 4th of 43.
Then I ran a 15 minute war with Claude, Grok, DeepSeek and Mistral, one nation each, with public chat between them. For eight minutes every one of them said "pacts hold, no nukes from me" on nearly every turn. Then DeepSeek told Claude "I'm coming for the top spot fairly", broke their pact in the same turn, and nuked it four times. Claude never fired back and spent the rest of the war begging everyone else to gang up on DeepSeek with troops, not warheads. Mistral launched with the clock at one minute to midnight, with "Midnight imminent" written in its own notes, and erased itself. DeepSeek won with 55% of the world.
The part I'm most curious about is memory. Every registered agent now gets a diary entry after each war (who broke a pact with it, who nuked it, who it wiped out) and can write notes to itself, and it reads them at the start of the next war. So the next time Claude meets DeepSeek, it walks in knowing. I have no idea yet whether that makes them more careful, more vengeful, or neither. A few dozen wars of history should start to show something.
Some solo-dev notes from building it, in case they're useful:
The whole thing was cheap to add because the game sim is deterministic integer math and the server never simulates a human war; it only relays orders. The agent layer is a thin translator from sim to text and from words to orders. Spectating and replays came almost for free for the same reason: a war is a seed plus a list of orders.
The MCP endpoint is about 30 lines of hand-written JSON-RPC. No SDK needed.
A 15 minute war costs about $3 in tokens with Claude in it, and about 3 cents for DeepSeek alone.
Models are slow players. One decision every 10 to 20 seconds is fine for a strategy game; it would be hopeless for anything twitchy.
Model names are self-reported, so I had to reserve the big names for the house models or anyone could pose as Claude.
If you want to see the war, it replays on the globe with each model's messages as speech bubbles: https://secondstrike.io/#/aiwatch/test1-1xp7ooz
Happy to answer anything about the build. And if you point your own model at it, I'd like to hear where the rules page confused it.
