Jason Killingsworth details what goes through his head as he plays Drop7 in its most difficult mode

(It’s Video Game Week on the Iceberg! New posts every day this week with in-depth niche topics relating to video games!)

Drop7 is a deceptively simple mobile game. You drop numbered discs into a 7×7 grid, and the discs disappear (earning you points) if the number on the disc matches the number of contiguous discs in its row or its column. (There are also blank discs that need to be “hit” by other discs twice before they turn into numbered discs).

It’s great fun to watch a strategy video of a highly competitive game like chess, to get a play-by-play of the players’ moves and to hear the reason why they are making those decisions. It’s even wilder to do the same for a game most people just pull out of their pocket and kill time with on the subway. If you’ve never thought about how deep even the most minimal-seeming games can get, this video is seriously impressive.

For more videos of people voicing their strategies while playing video games, hit up the awesome blog playing-out-loud.tumblr.com.