With only 26K* of space for the ARM code(ARM Thumb instructions taking 2 or 4 bytes each) and its data (which tends to be larger due to more detailed sprites, more colorful sprites, audio samples, 3-voice music data, etc.) efficient code is still a major factor. We spend a lot of time optimizing, with help from cd-w, Thomas, and others. John's currently doing a round of optimizing on Mappy.
* 32K - 4K for 6507 code - 2K for CDF driver. We only had 24K of space when we used DPC+. A major part of the design of the newer CDF that I'm using with Spice C was, surprise-surprise, to be more more efficient.
To me (and a large fraction of embedded linux coders out there and even more so any ARM microcontroller developers) this is completely different (and actually QUITE popular) game.
Even if you would write everything in perfect ARM assembler.
Not saying that it is trivial or even simple here.
If tools make things simpler: great.
But here these tools require major changes of the 'things'
Also totally valid. But something completely else.
Maybe not so much from the gamer's perspective who evaluates the game and not the code but I would prefer 'native games' with all their special charme and wit in game logic (dictated by restrictions and then embraced by the most knowledgable of the coders) over a game written in C running on ARM, using VCS colors and audio and still looking worse than any C64 game of 1982 (no offence
A VCS on steroids gets pretty close to a PICO8.
Restrictions for colors, graphics and also for ROM size, sure.
But the CPU is almost taken out of the specs. People do incredibly amazing stuff with the Pico8, no doubt.
Written in LUA which allows for a quick success and easy entry level. It oozes 'retro' visually but has yet nothing to do with it.
Sorry if I got carried away here
I am not judging what others do but I try to portrait a picture of how I see these recent developments with more than a grain of salt.
I too wrote some code for small ARM CPUs/microcontroller (not even SOCs). Partially in C but also in ARM assembler.