Okay, I've downloaded your game (despite of that applet...), and here is my personal impression after playing it through, and also some suggestions for improvement:
1) First of all, I like the overall atmosphere that you create with your drawn pictures.
2) Also the choice of music is very good in my opinion. Maybe it is set a bit too loud (I had my laptop at a minimum of volume, and the music was still rather loud, but it might be just my laptop).
3) I like the introduction with the simple animations, I think it's a very good start into the game, and makes it more interesting. Also using the animations later in the game is a great idea
4) In most cases when an action was available, the mouse pointer changed, but there are still some screens, where it's not the case yet. It would make the game much clearer if you could change this, so that the mouse pointer always shows if there is a hotspot to interact with or not.
5) There are two screens which have a strange perspective, and the player feels as being huge: the kitchen and the room with the 2 doors: you look almost from above. The pictures themselves are well done, but I had the impression of flying
6) At the moment (in this first demo) the players have not much choice, the linear actions (entering some rooms) are given. I hope that you'll create some more possibilities and challenges for the players as you advance with the game (e.g. picking up objects and use them, choice to enter rooms, something to solve etc.).
All in all, I think that you have made a good start with your game, and have done a good job. I'm curious to see the further developments. Good luck