Red7 is a free print and play card game from Carl Chudyk, designer of the legendary Glory to Rome. In it, you play numbered, color cards to either build your color palette or change the scoring conditions.
Nigel Lancaster has written a set of abstract modern air war rules called Instant Thunder, and has graciously permitted MiniatureWargaming to host them. This is a major work, with 28 pages of rules, aircraft and missle lists, and designers notes.
Magma is an abstract territory control print-and-play game from Invisible City
The Abstractionist is a free print-and-play board game for 2 – 6 players about artists creating color palettes for their abstract paintings. The core mechanism is tile laying.