I'm glad you enjoyed the UI. I have previous UI trauma that I'm just now starting to get over, so this is the first jam I've done where I've put genuine effort into it.
With the collision, we had it set so that all of the reindeer + sleigh had collision. It is possible some of our collision was too fat. Did you notice if it was a particular part of you getting hit or a particular obstacle that felt this way? For a while we had grids of snowmen so the corners being relativiely safe weren't a thing until the last minute. Oops!