The funding event will last one month and a half so maybe next month! Also paying 10 dollars will give you both full games on release (and only 3$ for demon's dream!) so don't hesitate to go for the cheap deal if you are out of budget!
Under the download button, It explained how to. You just click on view bundle and then get the bundle and donate money depending of the tier you want! Sadly sex with the enemy is not in the current workflow but who knows?
