IN FACT, you can have an animated character walk around the world, pick items up and do simple quests using NO programming at all- you just need blender and blender2crystal... There is already provided scripts to help you get up and running.
Afaik there will be some problems though. First of all you would use view aligned billboards and fake an isometric camera (like in isotest). Then when you load the billboards texture, you must match the ratio of the billboard to the loaded texture. Probably you will want to use a custom uvanim shader so that you can use a sprite sheet- this modifies the uv coordinates across an image so that you only display a subset of the image.
Sprite rpgs are the coolest but drawing sprites is very hard... Good luck.
Important Note: Version 3 of CELstart is the first one that works for python scripts. However there is still a limitation. You have to manually set the PYTHONPATH environment variable to point to the zip file (i.e. not the extracted zip file, just the zip file itself) that you want to run. We will try to fix this limitation in the future.
The next release is coming soon though hopefully and this will be fixed.