Humble Bundle offers downloads of the Humble Arcen 4-Game Bundle for Windows and Mac for whatever you want to pay. If you opt to pay the bare minimum of $1, you'll get AI War: Fleet Command with five DLC packs (pictured), A Valley Without Wind, A Valley Without Wind 2, and Tidalis. That's $29 under the lowest price we could find for downloads of these games elsewhere. Deal ends September 12 at 1:59pm ET.

If you pay more than the average, currently $5.80, you'll also get Shattered Haven and Skyward Collapse plus Nihon no Mura DLC. Your contribution can be donated to charity (Electronic Frontier Foundation, or the Child's Play Charity), the developers, Humble Bundle Inc., or all.

Of note, these games require a Steam account for activation.