If you see no meter skipping, there are no consequences. (In fact, I heard some wild theories about how the meter is supposed to run faster on brand-new computers. I hope that was just a false rumour.)
Yes, I played this game on a very old laptop not meeting the requirements, and everything was fine, as long as all other software except the one browser (Chrome) game window was closed. It's also very important to close the original browser window from which you launch the game pop-up window.
Faterson sez...
"It's also very important to close the original browser window from which you launch the game pop-up window"
I didn't know that...thanks for the tip :)