It has a little ads window on the side, and has Pay To Win or Watch Ad to continue. It also takes 235 MB of disk, full CPU core and 500 MB of RAM. Darn, Minesweeper for Windows 3.0 running on 8088 IBM PC didn't take all CPU resources.
@nina_kali_nina at least they're a little more honest than the games that say "watch a video" when they mean an ad
@aburka also tfw buying a new deck of cards for solitaire every month is cheaper than paying for Windows Solitaire subscription