The most common symptom I encounter on indie titles in particular is loading stutter. You can tell when something big is about to happen or you'll see a new enemy type because the game just locks up for a short but perceivable amount of time.

The 2nd Ori game was actually entirely unplayable on my system until I moved it to an SSD due to how it loads assets (don't know the details, but that's my assumption). I couldn't beat the time trials since it'd lock up mid-air due to the amount of map coverage and mess up my flow.