Skirmish
A specialist game for Age of Sigmar released in 2017 as an almost direct counterpart to Kill Team, in that it focuses on using small warbands of a handful of models, using rules that are basically just the main Age of Sigmar game rules modified for smaller, faster battles. Unfortunately, though typical of the various one-off specialist games of the time, Skirmish was very much a "fire-and-forget" release, fading into obscurity almost immediately with no further support since, although it is technically still available. The ebook version of the rules is still up on the GW website, and there is a rules FAQ and Warband Roster for download on the Community website.
With Warcry looming over the horizon, though, promising a fully supported and expanded skirmish game following the example of Kill Team and Warhammer Underworlds, Skirmish will likely end up following Shadow War's example and be completely swept under the rug before long.