This was done as an exercise in my QA class where we had to choose a small indie game, have it played for a short amount of time by people we knew (or not), gather data during the playing session and then realize a small QA with them to collect their feelings and compare it with the data.
We chose to playtest FUMES which is a fast-paced car combat game with a short gameplay loop and most importantly offers an emergent gameplay so it brings players to behave very differently depending of their experience (which is what we wanted).