A lovely short game! Playing it alone is tough (I kept expecting the arrow keys to control the character on the right side, and would often get stuck on walls), but is, indeed, rewarding. There is not much depth, it seems, in the gift system (not that it's needed), but its broadening would encourage replay as much as the uncontrollable human urge to see every caption based on the end score.
As a final note: the theming is supreme. The intro sets the mood perfectly, and the varied sources of power-ups are a nice touch.