You can jam even if you're tired
Normally @ruruie and I approach every LD as an operation, with extensive pre-conception of game ideas by theme finalist, time off work, full-time over the weekend, etc. This time neither of our IRL lives allowed such a focus. We had no time off work and were not rested. We decided to do it anyway and simply scope down as hard as possible and it turns out you can still make a satisfying game this way. It's worth doing an LD even if you think you can't do it 'properly' and you might find it refreshing to have permission to do a small trinket rather than push for a game bigger and better than your last. We also still learned a lot and used new features of the engine; it was surprisingly nontrivial to get the mirrors to work.
Also, we implemented beams (or more specifically, ruruie implemented beams while I was asleep), which is the second time I have said 'we can't have beams, they're out of scope, we need to triage' and then @ruruie will not give up and makes them happen. We even implemented cats.
(check the beams, the cats, and the game out here: https://ldjam.com/events/ludum-dare/58/witch-solar (we need one more rating to cover all categories))