We simply do a side by side comparison of the original game while developing SMC, so we manually tinker with numbers until it looks as close to the original as possible.
What about the custom sprites? (Because it looks official like its actually a charcter, do you do the same thing like with the original sprites? and isn't this replies was too long?)
The custom sprites are made by our spriter team, then we use its source material to determine its speed/general AI and interactions, but adjust to account for the gamestyle.
