Thanks for putting up a Linux version, worked great! I only got to see the ending #1 because the house is so large and same looking that I always get lost and eventually caught. Managed to get only 3 golden keys.
There is what I expect to be a bug - when you get chased in a hall way by Mary and dash away, you are faster than her but she get's pushed back into the screen whenever she reaches the edge. So I had all the other kinds on my tail, Mary appeared and I started to dash, but that only got all them poor kids killed. They were not fast enough or followed too far behind, it happened so fast I can't really say.
Story wise I think you missed a great opportunity. It starts promising with the invitation, greeting and introduction, but the turning point, the key scene where the summoning happens, is just told by a text passage that would be so much more thrilling if you'd get to actually play/witness it.