Kerbal Space Program | Greenman Gaming | £9.60 (RRP: £19.99)
Voucher Code: Z4364W-7MR5WA-N5BCOO
One of the earliest Early Access games is also one of the very best, and ironically most content-complete. 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 long-haul. Save a tenner with GMG's Z4364W-7MR5WA-N5BCOO voucher code.
Thanks to dealfinder extraordinaire jaystan @ HUKD!