I'm a big fan of online games and firmly believe that playing can offer significant learning experiences.
For those who enjoy open-ended problem-solving and systems thinking & design, here's an excellent (though not very well-known) game to consider:
Factorio invites you into an infinite 2D world where the aim is to build and create automated factories for the production of increasingly complex items.
It involves mining resources, conducting research on technologies, setting up infrastructure, automating production, and battling enemies.
The game challenges you to use your imagination in designing your factory, ingeniously combine simple elements into sophisticated structures, employ management skills to ensure smooth operation, and safeguard your factory from creatures that aren't particularly fond of you.
PS: it's complex, challenging, and addictive!
Read a relevant case study here:
Case Study: Why you should (maybe) play Factorio
Is there a game that is really beneficial for your real-life skills?
Also, here is a relevant tweet of CEO of Shopify:
You can either purchase the game or try out the demo version for free.