Hemmerling's Concentration. The CORE version of the card game "Concentration" ( "http://en.wikipedia.org/wiki/Concentration_(card_game)" ). A contribution to the "Global Game Jam Online 2021" ( "http://www.globalgamejam.org/2021" ).
Step #1 Download the "Core Launcher Install" Windows executable from the Core website ( https://www.coregames.com/ )
Step #2: Run the downloaded Windows executable,, so that the full "Core" runtime is installed on your computer. This might take some hours, indeed.
Step #3: Launch my game from the "Core" website, at "http://www.coregames.com/games/bcfb76/hemmerlingconcentration", using any standard browser ( Firefox, Chrome, Edge ). The installed "Core" runtime is executed to play the downloaded game.