I've played games that would, while running full screen, also show the current time and included an alarm you could use in case you got a little too buried in it.
I found them both effective.
When it comes to manipulation in media, games with subscriptions or MTX are more manipulative than games without simply because the owners want more of your money. It's the difference between, "Here is our game, how much money will you give us over x time? What if we tweaked this gameplay, and made this look nicer, and used FOMO while selling this cosmetic item, and made this piece of kit a today-only 'bargain'?" versus "Here is my game, like it or don't but it's already made." The latter feels like a more authentic piece of media than the former, which feels entirely extractive.