This romhack here holds many badly designed and very frustrating courses, plus a questionable design choice in ramping up the AI to near impossible levels.

• Most of your courses have incredibly sharp turns that usually lead into a wall or, in the Ghost Valley courses, falling off.
• Almost all of your courses do not fit with the names of your courses. Bowser Castle 3 is a Rainbow Road, Donut Plains 1 is a Mario Circuit, Rainbow Road is a Choco Island, etc.
• All of your courses during Time Trials still have coins, small optional jumps, oil slicks, and optional boost pads when they should be removed during the trial.
• Three courses, Ghost Valley 2, Donut Plains 3, and Vanilla Lake 2, have bugs that prevent laps from counting. The first two will not record the first lap until you make two passes on the course, making both courses require six laps. The last one will not count a lap if you fall off at the very end of the course.
• Bowser Castle 3 holds a course breaking bug. During the course’s red path, falling off at a certain point will cause Lakitu to carry you to a corner and will drop you into the abyss infinitely. This video shows the bug in action.
• As I said above, the AI is ramped up to nearly impossible levels. That, and due to the frustrating nature of the courses, makes playing Mario GP almost impossible.

With all these points above, the romhack is, overall, frustrating and unfun. I do not recommend it at all.