In Dreams builds itself out of the parts of old games that we read as unintentional, unhelpful, oversights, limits of a medium, poor design choices, and subsequently (half-)forget. Your game puts these parts front and centre, and uses them to great effect to create horror.
There's a particular kind of loss of control you feel from playing old PC games, particularly old shareware games of dubious provenance. Most are janky and unplayable, unpredictable. Some are less wholesome than they first appear. The audio and visual aspects of old DOS games are inherently uncanny and offputting, especially when done “badly”. In Dreams uses this feeling of wrongness to unsettle. It uses mechanics that take control away from the player and uses them to increase the feeling of horror. Frantically pixel searching is like being lost in a forest. Checking and re-checking the same clickboxes in the hope that they will reveal a way to safety does evoke the feeling of panic we would feel when almost alone in a remote place. Even the options on the right-click menu unsettle a little in their lack of function/context, and unsettle even more when they are taken away. Agree that the click-mashing can make you miss certain bits, but it's a game that still plays well second time round and BLEEDS atmosphere.
A surreal, frightening experience. I enjoyed playing this immensely!