Sine Mora $2 after 20% off code GMG20-PJFEW-Y16HK at GMG By w00py | January 4, 2013 0 Comment Green Man Gaming (GMG) has a new 20% off voucher code GMG20-PJFEW-Y16HK. Should work on anything without a cashback/creditback offer. Sine Mora is on sale for $2.49. Use the code listed above and the price drops to $2.00. The game uses Steamworks, so Steam activation is required.