i'd say, download playbasic demo, and learn how to create iso graphics, yourself. It's against AUP to ask about other game building programs here.
Playbasic is a good language for 2d games, and iso graphics are also not that hard to build. A simple isometric square 10x10 pixels is made by rotating it 45 degrees clockwise, and scaling it vertically 50%. Very simple. Heres a picture of creating a simple isometric crate.

Pretty Pixel Magic
Learn to code, and learn to build graphics, and you'll be set.
Start small, and simple, like i showed you. Don't try and make the next Diablo, you'll fail with much anger and hate towards game creation.
Good luck!
MOONDOG

current projects: Mystic Dream // red // battle room