Lovely game! Especially for a first Jam. It was short unfortunately, but everything included was very polished: the title screen, the atmosphere of the first level, the light/shadow effect of the second level, etc... The second level was especially well done.
I noticed a little bug: you can let go of your sister just before the transition (the second level still proceeds normally).
I would have loved to see more, I hope you will be doing a post-jam version (it seems you will looking at your replies), so I can check it out. :)