!! Disclaimer!! I don't have a Mac so I cannot fully test the process.
I've been told it's possible to play on mac with a PC emulator like WineBottler.
Here's the steps:
1 - Install driver for your controller
2 - Download WineBottler (stable version) and install (slide in app folder)
3- Open Wine ( use Command+Open since it's not from the AppStore)
4 - Open SkateRide (choose to open with Wine)
5- When starting the game, reconfigure the control with BACKSPACE at the start even if you got a xbox360 controller
NOTE: There might be another step needed where you need to install your game into an app with the use of winebottler and choose installation mode "copy file (program) and all files in the folder App bundle". It think it's related to your OS version.
Comment if you got issues or problems. NORLY got a mac, so he can help to debug.
Let us know if you got it working with something else.