I would say that the gameplay is a more simplified version of red dead 2. The base mechanics are mostly the same but red dead 2 adds more depth. In some ways I prefer the gameplay in red dead 1 as it’s simple to understand health, stamina, and dead eye work without having to bother with “cores” (there are no cores in red dead 1)

Eating and medicine is simply for restoring health, deadeye is refilled by getting head shots. No gun maintenance or inventory management needed in the first game.

The story is a bit more focused in the first game as well instead of strung out into chapters.