I guess I would have expected that the game would be using code written to use different time/space trade-offs targeting a system with 64K of RAM versus 2K. Unlike Warren Robinett's Adventure, where the bat, dragons, and magnets all need to be processed every gametick regardless of whether they're on screen or not, SMB ignores everything that isn't on the screen, and never really has all that much going on except maybe when the hammer-throwing dudes are on screen and if memory serves most of the rows of tiles on screen at that point are either blank or repeating.Bananmos wrote:I think you're missing the point here. The game doesn't have half the screen time or even a quarter to spare - it's already showing significant slowdowns in places, precisely because it is running code that was written for another gaming system, where the 6502 is clocked almost twice as fast.
If the game actually uses NES game logic, that would be interesting, but I'm not sure how one could sensibly make the game play precisely like the NES version unless one were to have objects either become active only after they've fully scrolled onto the screen, or cease to be active before they reach the left.