I've always been a sandbox player but I've had huge amount of fun playing the third Campaign mission on high difficulties.
On lower difficulties, the TAS Crusader and it’s support fleet can be used to overwhelm the Drengin and the missions can be done very quickly. However, at high difficulty, that approach is indeed Suicide, and you have no choice but to find another way. The problem is, even with the TAS Crusader and the fleets you start with, the Drengin have a huge power lead, and strong defences, so there is a lot of catching up to do. You’ll need to play well all round. It's also cool to get straight into the action. At least some of the exploits marigoldran has highlighted to break the game can't be used e.g. colony spam.
Highly recommended for those looking for fun that don't mind the higher difficulties. And for those with a competitive streak, good luck beating the score I just posted on the Metaverse at Suicidal difficulty without cheats.