I have ADHD, and with other game apps that I use to stim, the ads are more obtrusive and obnoxious, with an ad between each round. Not so here. The pacing is great, in that normal is slow enough to look over the cards yet fast enough to keep the game going, and is adjustable. Also, I had been playing for 3 days before the "rate me" request screen came up, which is infinitely better than the 30 seconds one generally gets.