Run back and forth while praying to RNG
Oof. I really want to like this game but no. At it's current state it is just a bad game.
In short, it's lighthearted XCOM with a single roguelike hero.
However, do you know what mechanic XCOM had that allowed gunfights to work even with misses? You could heal between missions.
Here - you have 5hp and it is not easy to get them back.
So you have to play really careful, but this is how a standard loop goes-
You hide behind something and wait for the enemy to fire and hope they miss.
Then you run up so you don't have atrocious %hit, take a single shot, then run back. And repeat.
Even basic enemies on the first level need to have 2-3 loops. And there's about 100 of them in the first area.
But THEN. THEN you beat the boss and go to the next.
Mostly the same with some different hazards. AND THE BASIC ENEMY HAS TRIPLE THE HP.
You will NOT be keeping up with it with your upgrades unless you are really lucky.
My guess is that they want you to grind the 1st boss like half a dozen times to improve your weapon, then breeze through the 1st area before attempting the 2nd. And repeat for however many areas there are.
No thank you.