Today only, Green Man Gaming takes up to 80% off downloads of a selection of zombie games for Windows and Mac as part of its Summer Sale. Coupon code "GRAB20-PERCNT-OFFNOW" cuts an extra 20% off. Plus, select games are bundled with a free mystery game. Most games require a Steam account. Deal ends today. A couple of best bets, with prices after coupon, and a free mystery game:

• Resident Evil 4 HD for PC for $6.40 (low by $14)
• The Walking Dead Season 2 for PC/Mac for $6.80 (pictured, low by $18)