Kerbal Space Program | Steam | £11.99 (RRP: £19.99)
Kerbal Space Program is still in Early Access, but is already one of the most unique and challenging games we've played in yonks. You're tasked with building rockets in a brutally realistic simulator, watching a thousand embarrassing crashes before finally creating something that can break the atmosphere. Which is where the real fun begins. Part edutainment, part puzzler, part simulator and all awesome, this will keep you going for a while - and you can save the best part of a tenner today.
A major update is also coming next week, apparently.