Gigantic Army is an arcade style run and gun shooter characterized by its attempt to emulate the heavy, powerful feeling of a gigantic mech suit.
The first thing you will notice about GA is that your mech stomps along at a somewhat slow speed. Your jumps too, also feel heavy and weighed down, even with your jetpack which allows you to continuously ascend further upward by holding down the jump button. All your weapons (including the proximity based melee attack) are balanced in some way too to be more methodical in use, some having brief reload times or requiring to be precisely fired with your 360 degree aim. You also have a ground dash, but it has quite some acceleration and must be used carefully. Lastly, there's the shield which can block enemy fire, but using it requires careful timing and planning as it cannot be brought up mid air, or immediately after landing or firing.
Do these limitations make Gigantic Army feel slow paced? Not at all. GA shows that player move speed and pacing are two completely different things, and that seemingly cumbersome controls can feel profoundly smooth once fully mastered. While your mech may at first seem like a big clunky hunk of junk, mastering the subtle physics and techniques of jet packing, landing, and dashing will allow you to pull off rad dodges and close calls as you blast enemies.
The level and boss design is also quite solid, with the bosses being a major highlight and the most enjoyable part of the game. The levels offer great variety, making up for your slow move speed by being tailored around quick dashes, jumps, and fending off enemies from both sides. They also do a great job of mixing things up with frequent mini boss encounters. The bosses, especially the later ones, are the real show stealers though. Each of them has a number of attacks which are tricky to dodge whether on the ground or in the air, and will have you weighing the strategic benefits of attempting to out space them on the ground or out maneuver them in the air, two options that require very different technique but are both challenging and rewarding.
The game does a good job in terms of replayability, too. There are two extra difficulties, which feature much more challenging bullet dodging action, and the game has a scoring system in which you are rewarded a bonus for how fast you can speed run stages. Each of the three available weapons also causes you to use a slightly different playstyle, so attempting to master the game with all three should add a lot of replay value for anyone who enjoys the game enough to do so.
I generally prefer more nimble, ninja like controls for my action games, but Gigantic Army shows that a methodical, heavy metal shooter can provide an awesome change of pace.