This version seems to be using slightly different rules: my recollection is that the original 2048 prevented a move if it wouldn't cause any blocks to shift or collapse, while this one spawns a block unconditionally.
A bit lazy approach, but also quite obvious. Pretty much what you'd get from a junior dev.
(Also if you're wondering about "// end of function ..." comments, I asked the AI to add those at some point, to serve as anchors, as the diffs generated by GPT-4o started becoming ambiguous and would add code in wrong places.)
I think it's also not progressing the block size with score: IIRC the original came also begins spawning 8s and 16s once you get above your first 512 block. But I could be misremembering.
(This kind of feedback driven generation is one of the things I do find very impressive about LLMs. But it's currently more or less the only thing.)
I don't remember it doing progressive block sizing - I only vaguely remember being mildly annoyed by getting to 2048 taking >2x the effort it took to get to 1024, which itself took >2x the effort of getting to 512, etc. - a frustration which my version accurately replicates :).
