The mirror does work; but unfortunately, we shifted the position of it a tiiiny bit immediately before release, and forgot to move the collider with it :(. We've emailed Lee and addressed the fix for this - thank you so much for bringing this up, and also for playing!
If you're interested in playing more, we've written up the solutions in an attempt to make the game a little more accessible.
Thanks again for playing, looking forward to checking out your submission!