The web version sometimes goes into a non responsive state when loading a world, if you press wait it should load up. Also, when creating a world it requires a seed in the seed number box (this was fix in the most recent version & the web version may be on a older version). I recommend installing the game as it runs faster and allows for saving. I restarted development again on the game so new updates will be released soon :).
Sorry for the bad first experience with the game, i hope you can give it another shot.