This wasn't bad for a 'first game' game, but I think it could've been a lot better with just a little extra work. As has been said, selecting inventory items was a bit of a pain. This could've been solved by using the same size icons for all items and adjusting the InvWindow's ItemHeight/Width properties as needed. And since you can now have different graphics for the items in the InvWindow and as cursor, you could still keep the current graphics for interacting with the scene. On which note, I had a bit of trouble knowing where on the Item cursor the hotspot was, which made using some of the items tricky (once I was actually able to select them, that is
). That's easily solved, though, by drawing the hotspot onto the graphic yourself, or having AGS do it for you. Also, it'd be nice if there was some indication of where/when you can exist scenes other than doorways (e.g. left out of the kitchen) - including side walls with doors would help here, or use hotspot labels, animating mouse cursors, etc. And finally, make it a little longer! I mostly enjoyed the mix of gameplay elements, but it seemed very short - which I guess is understandable from a first attempt game, really - and the puzzles where pretty simple (again, understandable).
I won't comment on the graphics - you've already said they're not the best (but maybe not as bad as you think!), they're not my forte, and they'll hopefully improve with time and practice anyway - except to say that, again, a little extra effort in adding details would probably make a major difference. (I'm thinking more about the amount
of things in the scene - currently they're a bit empty - than the 'quality' of the art...)
My, that felt like a long post, but you DID ask for comments.