If you own a ROM of S3&K, a patch file, and the patience to configure a modern emulator, this is the most essential Sonic experience since Mania . Just be warned: Once you loop at 1.4g, you can never go back.
Most "improvement" hacks add palettes, custom sprites, or brutal difficulty. does none of that. The "3C" stands for Triple Coded Calculus . The "Delta" refers to the change in velocity over time.
In vanilla S3&K, if you hit a curved tunnel at Mach 2, the game checks collision 60 times per second. Due to a rounding error in the original sine lookup table, you would lose 3.2% of your speed every frame when transitioning from a 45-degree slope to a 90-degree wall.