I don't know if anyone else has actually taken the time to explain why this doesn't work so I may as well go in depth.
Firstly, this may just be a problem on my end but when I get a game over and have to start again it takes me back to the preloader. I don't know what's going on there so sorry, I can't fix this.
So 'mouse mazes' have an inherent flaw in flash where pressing the right mouse button stops the cursor from interacting with the flash, allowing you to move it around over any of the walls with zero consequence. That's the kind of thing you can't really design around and if somebody wants to solve a mouse maze then they can do so - this is just something to keep in mind if you intend for this kind of gameplay to be a part of a larger game.
The biggest problem is that as soon as the level is cleared, the next level is immediately loaded, and this is where I question whether or not you even bothered testing the game because for whatever reason all of the levels apart from the last one have the end be in the exact same position, meaning once you solve one maze you've automatically solved them all. This isn't just easy to fix - either have a button prompt like at the start or just think a little when designing the levels - but also impossible to NOT predict, did you think the game was going to throw the cursor across the other end of the screen after clearing the maze.
The only advice I can really give you is to actually test your games before releasing them.