OP never said Claude made a whole game from scratch though, nor are they saying Claude is doing everything without any human contributing to the project, nor are they saying they haven't spent a lot of time and effort on it. Just that it's made it fun and more accessible and it's gotten them excited about something they abandoned.
Here's a bullet point list of the things Claude's done according to OP:
* it picked up the general path immediately
* he explicitly pushed into "lets have V0 game play loop finished, then we can compound and have fun = not giving up".
* [I gave him game design ideas,] he comes with working code.
* [I gave him papers about procedural algos,] and he comes with the implementation
* brainstorm[ed] items
* create[d] graphic assets
* he created a set of procedural 2d generators as external tools
* he even helped me build the lore.
Every one of these are plausible in isolation.