Turn on TURBO MODE or use phosphorus for speed: https://phosphorus.github.io/app.html?id=168382471&turbo=true&full-screen=true You can also press the d key to choose how much delay you want (click somewhere else on the screen to get out of any text boxes).
Yes, the mazes are impossible, but the point is that you can go between any two points since they are all connected. Also, this project is more focused on the beauty of each algorithm and not on making it a game... If you do want a possible maze, try making one corner the entrance and the opposite corner the exit. :) Check this blog out for more details on each algorithm: http://weblog.jamisbuck.org/2011/2/7/maze-generation-algorithm-recap.html