Sword of the Stars - Firestorm mod.
Here I was playing humans with antimatter drive and missiles, happily deploying missile heavy Destroyer fleets, when the Tarka AI arives with five Cruisers.
Thats ok! I've been beating back Zuul cruisers for a while now.
The Tarka's had Flayer Missile arrays, one hit from one of those kills a Destroyer outright, each cruiser carried two of them. I had thirty destroyers, and a Flayer array reloads every 10 seconds or so.
That was a rather painful lesson in the value of high level point defence and cruiser hulls.