Do one of two options

A) Working with a partnet, create a isometric gallery/museum interior, complete with pixel art.

b) Working by yourself, create an isometric building (exterior only)

preparation:

1: Work through the pixel freak tutorial on
isometric building.

2: Give a quick read through this very complete pixel art tutorial.

3: Grab a template if you need some help getting started.

project:

step 1: come up with a concept for art and space
step 2: draw a floor plan
step 3: build isometric interior from floor plan
step 4: design isometric art to go into interior
step 5: design non-isometric enlargement of art