I’m not aware of any others (I knew about Shroud of the Morrigan), but they may exist. You may be interested in this guy’s Youtube channel (unfortunately inactive for a while, but had good content) https://www.youtube.com/watch?v=B3Yj5-LOxXA
Will definitely check out the Kickstarter campaign.
I had several Irish language games that ran on Mac OS 8 in the mid-1990s; they might possibly run on OS9, but definitely not on any modern Macs. I don’t know of recent Mac games in Irish (but I haven’t been looking for any).