You have to revisit the White Towers after defeating Katash. The Kobold Blaster can be found on the very top of the tower (you'll need the Rocket Boots to access that area), but the Blaster will be broken when you first find it, so you'll need to take it to Thomas and have him fix it in exchange for 10 Moonstones.
One of the best flash games out of Newgrounds. I just wish I could out-run the final boss,but my fingers aren't dexteros enough for that. So weird to see it as a full Steam game.
