Hi, glad you loved Chapter 1 and thanks for reaching out! I've had a few Mac users get in touch, but because I really value that you guys cared enough to speak up, I want to give you a totally straight, honest answer.
Current status with the Mac version is "on hold", because I don't possess a Mac to develop, export and test on - Chapter 1 was weird in this regard because "it just worked first time"; it actually won't store your savegames on a Mac, but because C1 is only ~half an hour, that hasn't really been an issue.
Case 2 is orders of magnitude more complex in its implementation, so would require extensive testing and likely some bugfixing on a Mac machine (which is why I can't just ask someone else to export it; it'll require actual work from me to test and fix it up). I'm not certain that the Mode7 stuff will work, too, which might mean that on Mac, the game is slightly different.
However, when case 3 is finished, before releasing it, I want to release a "final" version of C2 which fixes all of the small bugs that players have reported, and will try and see if I can borrow a Mac from somewhere around that time, and maybe revisit this.
Sorry that this isn't the answer I know that you (and the other Mac players) would like; my desire would be to have NALE on every platform I can, for anyone who wants to play it - unfortunately that isn't always possible in the timescales I want.