Mr Xenocryst wrote to point out a lovely little Flash game called StormWinds from Hero Interactive.  It reminds me a little of the Steampunk setting in the Hungry City Chronicles as you are charged with defending your home in the valley beyond the mountain pass from the hoards of attacking airbourne enemies.  Each level sees you using your bought and maintained weapons to destroy helicopters, airships, blimps, bi-planes, hot air balloons and more.

There’s 25 levels in the basic version, (and may I recommend picking up the machine gun, and then a sniper gun – the cannon is a pain to aim) and some rather tricky levels near the end and a huge boss to defeat once you get there.  It’s not perfect, and I’d love to have been able to work out the ‘levels’ of my various weapons, but it’s definitely dangerous if you’ve got a couple of hours to spare.  Thank you, Mr Xenocryst!