I'm here to fill you in on why you might care about these.
These games are fun for their own unique ideas. I'll elaborate on each soon.
If you're looking for something ground breaking, such games exist on the site but that's not what's on sale right now.
GOG has a fun puzzle platformer that takes platforms in a new direction. You'll be literally spinning platforms to move around in Fez. Fez is this little blocky character you control who is stylish enough to have a red fez (like me!) but no other clothing (strangely enough). The world you platform your way through is 3D but you only ever play in 2D. The intrinsic mechanic that this game has to make it stand out is being able to rotate in a third dimension onto another 2D plane adjacent to the other plain you were just on. This is like rotating a cube and viewing each side flat faced in front of you, one at a time. You can pick it up for $4.99. Also with this or any other purchase on GOG get a copy of The Witcher for FREE! This is limited for only a couple days. Don't let this chance slip away!
You'll be laughing as you play the (not very serious) Surgeon Simulator 2013. Now, the goal (supposedly) is to preform a surgery carefully and not damage the organs in need of operation. Then, you realize nothing is functioning more accurately than a rage doll. With no accuracy, blood and body parts fill the screen. As a medical simulator, one may assume there is some level or realism and accuracy but be warned, this is a silly game. It does not take itself seriously at all. If you're in for a laugh this will probably serve you well.
Lastly there is a sale for a game called Lilly Looking Through. I know nothing about it, and that's fair because it's not available to purchase, by anyone, because it hasn't been released yet. It's a pre-order bonus is what I'm saying. I suggest you don't take this deal. I LOVE GOG and I want you to support them but not like this. If you don't know what your putting your money into why take the risk when you can buy something you're informed about. The purpose of this blog is to help you make better decisions when it comes to games (AKA not impulsive purchases). Buying Lilly is silly.
When you see pre-orders, just say....
If you want some real thought out reasoning for not pre-ordering games, TotalBiscuit has already explained the subject well.
Enjoy, play, rage! Circle of life.