I would play this game over and over just because of its art. The concept of pets and the management of pet-related resources is very fun and incorporates the theme very well. Controls are unnecessarily complex though (as others suggested already -- I would either give the keyboard an action button and/or give the mouse the ability to move the character around).
I also had a very hard time figuring both what to do and how to do it. A tutorial, like you discussed in a reply to a previous comment, would be good. But I suspect there are other ways to make the game more intuitive, like adding labels to material bars, or having a different tileset to represent the mind of the pets (now that I think about it... why do I have to enter a pet's mind to collect its poop? :D).
I would really like to see an improved version of this original game.