One thing I learned from writing Removr is that designing level maps is a lot more challenging than writing code. There are tools like debuggers & unit tests to verify code, but the only way to test a game level is by playing it repeatedly.
You can’t verify that a level map is ‘correct’ – it’s largely subjective and involves more art than science. A game level needs to be visually appealing and needs to be challenging enough to maintain interest while still being possible to win.