GitHub user riperiperi has written a great technical analysis of the graphics of the new release, and does a great (and much better!) job explaining the issues with high DPI scaling that I raised with this thread.
Essentially, it seems 1080p and lower is rendered at 1x resolution, so pixel for pixel as the original game while filling up the rest of the screen at that scale. (This results in very small rendering of UI for many people which is a valid issue that should be addressed, but I encourage those affected to report the problem in threads specific to that issue such as here and here)
At higher resolutions, the game scales the graphics up: 1440p is 2x, 4K is 3x. 3D elements are rendered natively, and sprites and UI are scaled up to match. From riperiperi's article: (I have bolded for emphasis)
At 4K DPI, this causes each sprite pixel to be tripled in both axis, with some odd exceptions. It's like playing at 720p, but with much sharper looking sims.
Interestingly, when zooming out with res scale active, the game will prefer to use the near view sprites... for everything except pools. This keeps things sharper when zooming out compared to playing at 720p, though with the 3x scale at 4K, the middle zoom is a 1.5x zoom, which introduces some ugly pixel scaling.
As I originally mentioned, I am fully understanding that this is an older game and I am not expecting completely new pixel perfect bitmaps. What I am hoping for, as does the author, is improvements to the scaling that they have implemented for 4K screens so it's less uncomfortable to view, and developing an in-game way to configure the UI scale and DPI/resolution per the player's preference for their screen size.
