Overview
About this game
First, pick the type of ship you want

Secondly, pick the type of weapon to equip to your ship

Then the ship is sent to the front lines to automatically fight for you.
Once in a while, you'll get a permanent upgrade.

And once in a while, you'll get a combat pick that could drastically change the outcome of the battle.

Time is a factor
In the early levels, you'll have plenty of time to make your choices as you learn what everything does. But as you advance throughout the stages, eventually you'll reach the game's natural speed, which allows for only 4 seconds per choice.
This game is really about looking at numbers really quickly, over and over again. However, there are times when strategic choices come into play, especially when dealing with point defense weapons, nukes, and other weapon types.
Additionally, planning out a strategy for your permanent upgrades early on will help you win in the late game. Actually, I'm not sure if the game is beatable without planning your permanent upgrades.