I've just uploaded Build 282. This build should have significant performance improvements for everyone.
After some people reported the game running slow last build, I spent a long time to look for the source of the problem, and I've made a fix which I've tested on multiple machines and improves the speed a lot. Please try the game out and let me know how it runs for you.
Additionally, I fixed a couple of minor bugs in this build:
* fixed bug with "Next Build" information not coming up (after dragon)
* fixed dagger not showing up in "Freedom"
You can also press F12 during the main game to see your framerate. It should be at 60 for an optimal experience. Pressing F7 will turn off lighting effects.
If you do not see "Build 282" in the bottom right of the main menu, restart Steam to force an update of the game.