(Note: I have barely touched this game on Steam, however, I have played it before, off of Steam - mainly the demo, which you should check out).
Gimbal is a cool little top-down (mainly) Multyplayer Spaceship Combat Game. Using a nice creation suite, you create your own little Fighter by dragging and dropping, rotating and such of individual modules - pieces of steel & armor, wings, weapons, energy/engine related parts... You have a lot of freedom to create various designs this way, both simple and complex, and thus create your own personalized Fighter - it may be good for long-range bombardment but thus be frail or slow-moving, it may be good for dogfighting, it may be good all-around... Lots of choices! Yes, of course, you can totally screw up too and make a barely functional ship, but doing that and then learning from it is obviously part of the fun!
The gameplay itself is somewhat simple: You control your own ship and, along with your teammates, battle opposing ships in various game modes. When it comes to the gameplay itself, you move your ship either by keyboard, controller, mouse. Movement and combat are quite difficult at first, especially if you didn't make the best of ships - but thankfully, it is still easy to learn and improve, and you will eventually become an experienced pilot - which is ever so satisfying.
Some important things to note: You can zoom out *a lot*, you can use your radar to detect enemies and allies (teamkills *will* happen), ammo is limited (or you risk making your ship too slow if you overload it with ammo) and a lot of the fighting can be relatively long range, since taking damage is easy - and it cause modules of your ship to fly off, thus, making it harder for you to control it and continue fighting. Obviously, this means that you will be smart to play it safe.
To summarize gameplay itself, I'd say that, for starters, you should play regular Deathmatch, with loads of bots (due to map size) and that you should use the 3 preset ships available to you at Rank 1. Given that constructing a proper and fully-functional ship can be tricky, this is the best way to learn.
It is also very important to mention that the game has a progression system, meaning that you will have to grind for a while until you fully unlock all customizable parts *and* increase your Ship Budget (similar to Call of Duty!).
Game modes, from what I recall, are mainly focused around your team and you fighting the opposing one in a simple Team Deathmatch - the kicker, though, is the fact that both teams have large Motherships/Capital ship. Depending on game mode, these are either your target or they are mainly an obstacle to deter you from diving in deep. There are a few more modes, all based around eliminating enemies, their Capital ship or Capturing the perennial flag. There even seems to be a "Race" mode of some description.
When hosting a game (online or offline versus the AI) there are a lot of options to tinker around with - the basic being, of course, score limits, respawn timers, as well as more game-specific stuff, like limiting the upper-level of Ship Value or - more interestingly - editing the weapons that the Mothership/Capital has. It is also important to note that the maximum number of players is very high - 64.
The game has simple but detailed and well-drawn sprites for the ships, as well as very nicely made particles and other assorted effects for ship movement and combat - it is satisfying to watch your ship "drop in" (I assume from hyperspace) and watch it glide into the battlefield, with nice little visual details emphasizing the speed at which it enters - and then later, once you actually start flying it, admiring everything from the thruster and weapon effects to the pretty (but simplistic, it's space after all) backgrounds.
I am not much of a music guy (don't pay much attention to it), but I don't remember anything particularly bad or good about the game's music. The rest of the audio is fine - I'd single out the satisfying sound effects that you can hear from some of the heavier weapons as well as from the destruction of (enemy, heh) ships.
The game options are fine and you can, of course, customize things like resolution, graphics, audio (note: No Audio Sliders, only a separate On/Off for both Sound and Music).
The game, unfortunately, has two (related) issues:
1. It lacks players for Multyplayer
2. It lacks a true and long Singleplayer mode to make up for it.
As it happens with small indie games that don't get exposure (If only someone *cough* TotalBiscuit *cough* had covered it), the playerbase is small or non-existent. The potential to organize a playtime via the Steam forums or something is there, but, still, you can't just jump into the server browser and play a game.
Thus, you are left to play versus the AI, which aren't of noteworthy quality. All of this means that, of course, the game doesn't have a lot of time to offer you...
For the end I'd say that this is a fun little game which is "ruined" by the lack of people to play it with. The aesthetic, graphics and audio are good, the gameplay is challenging and satisfying, the customization is present and very important, like any good Multyplayer game there are a lot of options to make your own personalized game server... But basically all of this is for naught given that you won't have anyone to play it with. As of right now, there are 3 people online!
Still, you can potentially have some fun with it if you just screw around with the bots. It's still really charming and satisfying to glide into the battlefield with your own customized Space Fighter, awkwardly fly around your teammates and try to shoot your enemies - and, as your mighty cannons utterly annihilate a teammate of yours by accident and as the silly AI bots shoot you and destroy your steering modules and/or thrusters, you can then revel in the silence and loneliness as your ship slowly drifts away from the battlefield into the nothingness (since the AI failed to finish you off), thus forcing you to suicide and redeploy. The pretty aesthetic and relaxing, minimal sounds only at to this weird calm feel.
Cool game, pick up if you want to screw around with it a bit or if you happen to have 10+ friends ready and willing to revitalize it.