The reason i picked 3D over 2D is because its less work, the monsters are going to have a lot of animations - so i created the animations using bones in 3ds max, and then all i need to do is create a new 'model' for each monster, and it'll automatically be animated (i will tweak the animations a little to better suit each monster). also i can just 'rotate' for each of the directions it can be facing, so no need to re-draw it for facing each direction.
im a rather lame 2D artist, so trying to draw good 2D animations would take me far to long, and on such a small screen i can just make a crude 3D model and it looks acceptable when shrunk down etc.
the project is coming along really well (for me), it's probably only about 10% complete but i'm happy with the direction its taking, i animated the debug monster (the stupid robot fellow) and i'm happy with my AI/object interaction code so thats done and dusted.
i recently coded some basic physics in, so objects have a weight and the monster can shove them about or throw them at one another etc, graphically its fucking ugly but thats something i can work on once the coding is done.
given a few more weeks i think it'll be a basic virtual pet game, then i can start working on the combat/games/trading aspect, plus all the mini games etc.