Hi Sargas, I took the time to download the capx and to try the game link on dropbox and on Arcade; I'm experiencing the same kind of issues, as I posted in my own thread yesterday evening; sorry I didn't read your one before, I could have just replied to it instead! :)
I was kinda sure my problem had something to do with touch events but from your capx I see you use none.
As you did, I used vanilla C2, no third party plugins.
Which version of C2 are you using? I'm using the r140 beta.
This is the link to my post if you wanna read a better description of my issues and compare them with yours: http://www.scirra.com/forum/game-behaves-weird-in-arcade-but-fine-as-website_topic73340.html
I hope someone will answer to us and helps us fix this problem. By the way there are other issues too in Arcade/Forums (badges, game previews not updating, descriptions not updating everywhere, maybe there is a connection).
Have a nice day,