To keep things in the theme of Sierra releases, we decided to launch the old Dynamix/Sierra games promo this weekend. So if you're feeling like mind-bending and brain-twisting puzzles is your thing then grab yourself The Incredible Machine Mega Pack for only $4.99. And if flying biplanes and fighting with enemies during World War I is your thing than you have to pick up Red Baron Pack for only $4.99. Two great game packs 50% off! The promotion ends on Monday, February 15 at 11:59 p.m. EDT. It's not a bundle promotion, so you'll receive the 50% discount if you buy one or both titles.