When I read "Avoid the reflections", my first thought was "Wait, why do I need to avoid them?". Walked in front of the first mirror and I actually jumped from the scare.
The atmosphere ended up being super eery and creepy, but that first regular section ended up being super easy on repeat playthroughs once the initial shock passed and when I learned you can just walk past the mirrors with no consequence. As for the dark section, the platforming and enemy challenges seemed a bit simple with a little patience, all except for the section at the end with the spears. It seemed a little unfair that there was no indicator when the row of spears was gonna come from the ground or the sky besides those first initial spears, but it really wasn't that bad considering how there weren't too many of those, so no harm no foul.
I feel like the way you used reflection was really clever, where your reflection was after you, and where you had to become your reflection for the second section (at least that is how I saw it). This game I feel would be especially amazing if you had a chance to flesh it out with more levels and a story, but for a game made within the week timelimit, it was pretty good.