1. Enables the SA-1 chip on your ROM and modify almost all SMW engine to make the sprites (including non-standard) and blocks processed by SA-1, killing almost all slowdown on level and overworld and decreases the level loading time. And as a bonus, it increases the maximum number of sprites on screen to 20 and per level to 255.
2. Optimizations to the circle routine used on level ending.
3. Almost all slowdown possible in-game disappears.
4. Increases the maximum amount of sprites *on screen* to 22.
5. Increases the maximum amount of sprites *per level* to 255.
6. Moves the sprite processing code to SA-1, making all sprites gets processed 4 times as normally
7. Optimizes some routines to make the level loading faster.
8. Moves almost all non standard sprites, such as shooters, generators, cluster, extended, minor extended, bounce, score and smoke to SA-1 CPU.
9. Moves the block/map16 handling to SA-1 CPU.
10. Moves almost all overworld code to SA-1 side, leaving minimal CPU usage on overworld.
11. All other SA-1 features like 6 and 8MB support, 10.74 MHz CPU, Character Conversion DMA, fast RAM, etc.