While not too in-depth on the technical side of things, the developer of Siralim [Official Site] and Siralim 2 [Official Site] has blogged about supporting multiple platforms.
Interestingly, it seems GameMaker Studio 2 can make cross-platform development really quite simple, to the point that the developer said porting to Mac & Linux with GMS2 is "just a few clicks of the mouse".
The especially interesting parts are when they talk about Mac & Linux. As I always thought, people with a Mac tend to hang onto them for quite some time making ports a bit of an issue since they don't often have a powerful GPU:
One frustrating part of developing games for Mac, however, is that despite their high prices, Mac systems tend to be pretty weak from a hardware perspective. I’ve also found that people like to hang on to their same MacBook from 10 years ago and expect games to run perfectly well on it, so this is a good time for me to start optimizing the game to make it run more smoothly on lower-end hardware.
I've heard from a number of developers now that Mac specifications end up being an issue. Linux has the advantage there, since it can be run on practically any system as it's not locked-down. Not only that, but the developer had some kind words about Linux users to share too:
Linux tends to be a lot easier to work with. For obvious reasons, Linux users tend to be some of the most tech-savvy of all our players, so they’re really good at reporting bugs and crashes with a lot of detail. Linux users also tend to run this OS on higher-end systems, so optimization is typically not as big of an issue as it is with Mac devices.
Find the blog post here.
Uhhh, please don't make this an excuse for badly performing ports, pretty please!
Linux users also tend to run this OS on higher-end systems, so optimization is typically not as big of an issue as it is with Mac devices.
Uhhh, please don't make this an excuse for badly performing ports, pretty please!
*looks at my Athlon(tm) II X2 250*
Sounds legit.
Linux users also tend to run this OS on higher-end systems, so optimization is typically not as big of an issue as it is with Mac devices.That's not what I got from it, it read more like optimization is harder the lower the specifications = Mac's end up being trouble there.
Uhhh, please don't make this an excuse for badly performing ports, pretty please!
Still don;t consider myself very tech-savy despite actually working in IT.

That's a nice story but how can performance be an issue with graphics so simple as these games (Siralim 1 and 2)? They are oldschool.
To quote the blogpost linked to (twice):
Many people think that, because Siralim has such primitive graphics, it should be able to run on any system, but that’s simply not true. Siralim has a lot going on behind the scenes: the game needs to manage thousands of objects at a time, generate random dungeons quickly, and process tens of thousands of lines of code during battles thanks to the hundreds of spells and traits available to players at all times. This means that the player’s CPU and RAM are the most significant bottlenecks. GMS2 has a nice debugger that allows me to profile the game and determine which functions take up the most RAM and tax the CPU the hardest.Or put another way - the graphics has less to do with performance than the mechanics.
This is quite common, take a look at dwarf fortress for another fun example, in its default mode the graphics is about 15-30% and the rest is just the mechanics, and the mechanics part increase as time progress and more items are in play.
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