Here's another game I have played a bunch in 2009-2010: Hammerfight (it was also known as Hammerfell at some point, but it got changed for obvious reason). It's a physics based 2D arena fighter where you fly some kind of fantasy medieval contraption and try to smack enemies with oversized swords, axes and hammers obviously until they die. Super fun, but gets too hard at some point, never managed to finish it back in the day.
The game was actually developed by the guy who later made Highfleet, as I discovered quite recently.