How well they run will depend more on your GFX hardware.
What mj2c said.
The most important thing for new games is the graphics card, not the Windows version. Moebius works fine on 64-bit Windows 8 as long as you have a reasonably good graphics card. The GOG version of Dreamfall is supposed to work with Windows 8, though if you have a disc version of the game it may need patching.
Most adventure games expect an Nvidia or Radeon card with discrete memory (not shared memory) and at least medium capability (not a budget card or a card designed to save power). Drivers for Intel graphics are not always supported by adventure games. Casual games are less picky and will work with pretty much any newer computer.