Hmmm... I never play in this fullscreen mode, and so am not familiar with what it's behavior should be like.
However, in full screen and on its main page, it gets stuck with the "loading sound" message at my end. Skipping that, the game loads, but it won't recognize me as being logged in -- even though I do allow cookies for cache.armorgames.com . Strange. Then finally, I get a screen featuring all the text captions and such -- but the actual visual gaming screen itself never seems to load.
In normal mode, it loads and plays alright, but I still don't get recognized as being logged on (so have to play as guest), and that initial "loading sound" now seems to kick in alright, but takes forever to load. Skipping it again, the game plays, but of course without sound -- even though it suggests somewhere that the game will now load its sounds on the fly, instead.
All pretty strange. WinXP, Firefox 26 here. Tried the latter with add-ons disabled, as well.