Technically, Housekey, Part I is not an incomplete game, but it is certainly one in spirit. It's a skerrick of a my apartment game which has three locations and no housekey. The PC has left this item outside and is theoretically trapped in the very house in which they live. How ironic!
The house contains a handful of unsurprising and useless items which are consistently described as being beneath the PC's attention. Should it occur to you to try and leave your house via the front door in the manner of a normal person, an event of great unexpectedness will send you hurtling towards the non-existent Housekey, Part II, your mind racing with questions like, "Where did I put my housekey?" and "What?!"