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.