PLOT: There's a war or something.
Gigantic Army is a love-letter to NCS Masaya and their Assault Suits series. This might be before your time, but have you ever heard of Cybernator? Target Earth? Gigantic Army is designed much the same way. This is a mech shooter, but not that flashy Gundam Wing crap. The kind where all the mechs fly around looking beautiful, while J-POP plays in the background. This is more along the lines of The 08th MS Team. The best words to describe it are a mixture of CRUNCHY and CLUNKY. Let's call it CRULUNCHAKY.
Usually an action game being called CRULUNCHAKY is a bad thing, not so with Gigantic Army. All the mechs in this game have weight. Within seconds of starting the game you really gain an understanding of how the MECHanics work. Every movement in this game is calculated, and playing effectively is knowing when to "lead" enemy fire away. Raw reflexes are fine, but your mech is a bit too slow, heavy, and bulky to make those tight dodges. For the most part, enemies aim their guns at you when they fire, and larger mechs have a plethora of weapons they cycle through. Truly understanding this game requires predicting every possible attack, and then moving into position to do the full amount of damage. The nice thing about all that I just said, is that it's alot easier to figure out in-game. Gigantic Army has a natural level of difficulty. If you play smart and don't rush things, you'll get far.
Upon starting the game you get to choose your primary and limited secondary weapons. What you choose decides your style of play. Do you want good crowd control, don't mind long mini-boss fights, but want to finish end-bosses quickly? Go with the spread shot and laser cannon. For anything that gets too close you've got a pile-bunker. Expect the jump, hover, and dash abilities to see a lot of use as well. When all else fails, bring up the shield to block enemy bullets. An important thing to keep in mind, is that you can't block while jumping. Think of it as a commitment, choose one that suits the current situation.
Unlike Target Earth aka Assault Suits Leynos, the missions in Gigantic Army don't have any real objectives. There's no escorting, protecting, or any of that nonsense. Reach the end of the stage, and destroy everything in your path. There's a time-limit to keep you focused, power-ups along the way, and occasionally there are mines. The bosses are well-designed. Some move around a lot, others rely on their superior firepower, and there are even a couple unique fights. This game moves and ends very quickly. If all you want to see is the ending, this game will last about as long as the average 16-bit action game.
But that would be too easy wouldn't it? Upon completing the normal difficulty you'll unlock hard, and eventually insane. Enemies pack more firepower, you'll run into some new mechs, and the action gets hotter and heavier. Also you're expected to bring your SSS game if you want to get those high-score achievements. Move fast, don't take any damage(NONE), and kill everything. Sure it might be what you've been doing since you started the game, but you've got to do even better.
Gigantic Army is a very solid game. I highly recommend it to fans of the aforementioned mech-shooters, but really anyone can enjoy it.