Doh! I love the concept of browser games, as it's cross-platform and download free, but maybe this is a solid argument for also releasing a desktop version.
Several people have mentioned the up attack controls, so there's definitely room for improvement there. I tried added the "red skulls" on the city level to show the bottom, but I guess that's not quite enough, hehe. Though the only big "pit" is under the central skyscraper.
Thanks for playing, and especially thank you for the feedback!