Good job on the game. The difficulty seems balanced enough; I was able to beat it with some effort.
What I disliked:
Maze-like level design didn't feel very compelling. Camera seems "too zoomed in" so it's hard to spot the incoming baddies.
What I liked:
The narrative (the sister's dialog box) explains her mechanic very succinctly and well. Most important of all, once you lose a sibling you DEFINITELY feel out-of-control, so in that sense, the game's a resounding success!