There are a pair of Humble Bundles of interest to game developers launched today on Humble, the Game Design and AI Featuring Steve Rabin bundle and the Complete Pixel Art Online Course by Mammoth Interactive bundle. The first is a large collection of some of the coolest game development ebooks I have seen in a bundle yet, while the second is a collection of game development courses on creating Pixel art mostly using the free Piskel pixel art application.
The Game Design book bundle includes the following tiers:
1$ Tier
Game AI Pro
Games as a Service How Free to Play Design Can Make Better Games
Mid Tier
Game AI Pro 360: Guide to Character Behavior
Game AI Pro 360: Guide to Movement and Pathfinding
Making Deep Games
The Craft and Science of Game Design
Game AI Pro 2
The Pyramid of Game Design
We Deserve Better Villains
18$ Tier
Game AI Pro 3
Game AI Pro 360: Guide to Architecture
Game AI Pro 360: Guide to Tactics and Strategy
Game Design Deep Dive: Platformers
20 Essential Games to Study
Vintage Games 2.0
Game Design Theory: Philosophy for Understanding Games
Game Engine Gems 2
Game Engine Gems 3
As with all Humble Bundles, you decide how your funds are allocated between Humble, charity, the publisher and if you so choose (and thanks so much if you do!) to help support GFS using this link for the Game Design books, or this link for the Piskel Art courses bundle. You can learn more about both gamedev bundles in the video below.