Absolutely loved both of them! I think UFO Defense was the first pc game I played on our first 486. It was one of the first games I ever successfully hacked.

Not sure how many people know, but there’s another game from Gollop, Rebelstar Tactical Command for Gameboy Advance. It’s part of the Rebelstar series dating back to the ZX Spectrum. It plays pretty much the same as the original XCom games.