Grok 4.5 vs Meta Muse Spark 1.1 vs Fable 5 vs GPT 5.6 Sol

Same prompt for all four: "Build Minecraft, but it’s a modern AAA title built for playing in the browser. Focus on performance, complete functionality, and at least a 5 minute vertical slice that is playable. Punch trees, make planks, build crafting table, make wooden pickaxe, mine stone."

Results: Claude was the best but took 1.5 hours, Grok fastest at 8m29s but also worst quality and functionality.

Full write-up and all 4 are playable in the link.

Any ideas on what to test next, or how to handle a controlled experiment with follow-up prompts?