It seems like the only viable strat is to nuke the enemies after a while and then settle for whatever score that results in. I upgraded the power twice after doing so and then the enemies were somehow still too tough to do anything about.
Thx for playing !
Acually, there is a strat and it is not to use the nuke in the beginning.
Hint : upgrade reloading time first.
But the game is meant to survive as much as you can, at the end you will be beaten.
