What makes Debian so different from its derivatives that gaming on it is almost an heroic task to achieve?

A few years ago, almost out of despair, I moved away from Debian in order to be able to play a few games natively.

On those days, the main concern with running games on Debian came mostly from unavailable dependencies or older, incompatible versions.

Fast forward today, returning to Debian, all installers from GOG run smoothly, with no error, but many games report errors on launching.

So, as per the title, what crazy voodoo magic is cast upon Debian to create Ubuntu, Mint and others, making those derivatives gaming-capable but their base distro not?

Can someone enlighten me on this, please?

Out of many games I tried, I managed to run three: Kingdom Rush and the Frontiers sequel and Martial Law.

Other titles failed miserably, including Desperados, Eschalon and even Stardew Valley.

Because it's useful/required info:

system

• AMD Athlon II x2 250
• 8GB RAM
• GeForce G210

It's a very reliable work horse, with maxed out memory. The GPU proprietary drivers are no longer available; running nouveau.

When launching from the console, I get this report (example from Stardew Valley):

start.sh: 7: Bad substitution

start.sh: 9: source: not found

start.sh: 12: get_gameinfo: not found

start.sh: 13: get_gameinfo: not found

start.sh: 14: get_gameinfo: not found

start.sh: 29: define_option: not found

start.sh: 32: standard_options: not found