I was thinking about this. One way this could be countered is at somewhere between turns 334, and turns 600 mega events, galactic events, galactic council bills, and anomolies get changed to a new database of totally different types. This would change the game where it all of a sudden felt different. You.could also increase the difficulty of mega events this way as the player would be better equiped to handle this. As far as planet exploration changing the planetary events for extreme planets would work. Later down in the tech trees add totally.different stuff that cant be found early on in the tech trees. I think this would go a long way to change up the game. Doing things like instead of starting out mercenaries, and precursor artifacts found in planetary exploration with really strong bonuses, but letting you work up to this through levels would be better.