Gratuitous Space Battles is a very pretty game. The ships and modules are all rendered in a smooth, painted style, with the effects being very good but not so flashy that they disrupt the entire screen. It can get a little difficult to see the on-screen action sometimes thanks to all the effects, but that's more an issue of quantity than overwhelming visuals. The sounds are low-key and almost boring, and are the weakest part of the overall experience. The music is also entirely throwaway and generic, without any catchiness whatsoever. Gratuitous Space Battles is not a game that will inspire you to listen to the music outside of the game.
Gratuitous Space Battle removes all of that negotiation and resource management of the real-time strategy genre in the actual battles. However, you still manage resources in a meta-game aspect, even if you don't do it inside the fight itself. This meta-resource management revolves around the unlocking, upgrading, and designing of ships to fit within certain parameters. Once the design is done, you fight, which gives you more resources to unlock more modules. The cycle continues from there, leading the game into a perpetual feedback loop for those that get addicted to its charm of fighting without cause.
The most major part of the game is the designing. This is done in the appropriately titled ship design screen, and while it looks complex, it's actually fairly simple. A ship needs power, crew, weapons, armor, and engines. Combining all of these things in different ways gives you different variations on a ship with the same chassis. For example, if you want a ship that will act as a lure for the enemy while your other ships pound on them, load it down with armor, shields, and countermeasure weaponry. The only two definitives necessary to have a finished ship design are crew and power. If your crew or power needs exceed your supply, you will be unable to use the ship in the upcoming battle.
Weapons in particular have a lot behind them, which puts them above the rest of the modules. Every weapon has quite a few attributes, such as radius of fire, turning speed, speed of projectile, projectile type, damage, accuracy, weight, and much more. Every weapon must be carefully balanced to make sure that the ship in question isn't completely useless. However, if you load the ship with too many types of weapons, it won't be able to do anything significant thanks to its jack-of-all-trades status. Keeping this peace between specialization and diversification is extremely important in Gratuitous Space Battles, and is one of the core concepts of the game.
Let's assume that you have created several ship designs and now want to give them a trial run. You can do this with scenarios. Scenarios are both the campaign and the training in Gratuitous Space Battles. They reveal the weaknesses of your ship design while giving you the incentive to continue further through unlocking new modules, ships, and races. There are two kinds of scenarios in the game: normal and infinite. Normal is a simple fight to the death (or surrender), while infinite lasts (with increasingly harder AI waves) until you end it. There is also a challenge mode, which is not a part of the single-player.
Scenarios are defined according to ship limits and cost limits. You can have a few really expensive ships or a lot of cheap ones, and it's rare that you will ever feel overgunned for a fight. Gratuitous Space Battles is tuned just right in its scenario design, which means that you will never feel like you won extremely easily. It's almost always a fight to the wire, even on the easier difficulty, and the game is downright punishing on hard. It's so satisfying to see the end, however, with the debris floating around and the enemy ships dead in space or fleeing as broken husks. Anyway, when you start the scenario, you can place your ships, tweak their behaviors (which amounts to "target this first") and click start.