I did. Brother-in-law, gf and daughter!
My post-mortem will detail this, but evidently, I had a completed game on Day 5. Just not the same game I've ended up delivering on Day 7.
My gf actually playtested the core mechanics and a dummy level as early as Day 3 I believe.
My game was a very simple concept, but key is execution, and even at the scale of 7 days, you need playtesters because you become too familiar with your creation.
My gf is actually a decent gamer, so when she started struggling with the previous version of the rotating pencil, I knew I had erred.
Believe it or not, the pencil used to rotate twice as fast, and there was no save between the pencil and actual moving erasers (and even these were tougher to beat as the surface was not nearly as large). She made me avoid this critical flaw in my game, even though I, actually managed to beat that sequence relatively effortlessly.
Play-testing is critical. If you don't have time, TAKE the time :)