Heartwarming Moments: In the mission to attack the insect queen, you hear a panicked unit call Command for help, stating they're completely alone. Command tells them to sit tight and wait for help, just before losing contact. You might think this is leading up to the unit being killed off-screen, but instead you find a single flamethrower soldier waiting for you not far from the queen's chamber. He sounds especially happy to see you.
Demonic Spiders: Literally! Giant spiders can leap through the air like grasshoppers and fire life-sapping strands of silk that pulls you towards them, in addition to leaving webs around that can also drain your health if you get caught in them, thus hampering your movement.
Red Ants have more than three times the health of Grey Ants, move twice as fast, hit twice as hard, and can grab you and your squadmates and tear them around like ragdolls with their charge attack. Unsurprisingly, any level that features them tend to be among the hardest levels in the game.
Most Wonderful Sound: The six "EDF" chants in the voice command list. If you're leading an AI squad, using it causes all of them to instantly chant "EDF" with you, as if on their own accord. Chants of EDF! EDF! will override all other voice lines and drown out all other sound.
To a lesser extent, if you have a squad, you can issue commands to them with the multiplayer voice commands. Granted, they won't actually obey them, but hearing them respond "Yes sir!" in unison to you at least makes you feel in command.
Narm Charm: Earth Defense Force 2025 is a giant love letter to the science fiction B-movies of the past. Naturally this extends to the dialogue; every line of dialogue is either purposefully overdramatic or completely failing to be dramatic. Most of this is due to EDF troops making macho boasts without the macho voice to match, making them come off like complete dorks.
One of the things you can do in the game's voice chat is have your character sing an EDF battle anthem to the tune of Battle Hymn of the Republic. The lyrics are goofy, but the song is catchy and sung with such enthusiasm that it's hard not to love it.
Nightmare Fuel: The third trailer of the game introduces an enemy type that resembles the Asian giant hornet, the world's largest and dangerous hornets known to man.
There's a couple missions in the game that take place in an enclosed cavern. The first has your accompanying soldiers desperately fighting to survive and escape the trap, the latter has Storm team completely cut off from all other troops as Command tries to send reinforcement their way. All while a massive number of enemies close in.
That One Level: Mission 23, "Giant Robots", is the first mission that will likely take you several tries. You have to fight off three waves of Hectors, many of which are the deadly plasma cannon and rocket variants that can knock you around like a football as well as severely damage you, and even the ones who "just" have machine guns can chew through your health like paper. In addition, the Hectors will more often than not reduce your NPC squadmates to mulch in a matter of seconds, meaning you'll most likely end up having to fight the Hectors and their devastating weapons all by yourself.
"Void Ship" is particularly insidious as its initial goals lull you into a false sense of security; just take out several waves of the new Advanced Dropships. The problem, however, starts with the second wave. There are three ships in the second wave, but as soon as you down one of them, three more immediately spawn, one of which spawns the infamous Red Ants. The sheer density of enemies will shred most, if not all of your squadmates, leaving you all alone to face the constantly respawning horde.
Polished Port: The Steam release of 4.1 performs even better than the PS4 version with an actual stable 60 FPS like what was promised in the PS4 version even in high-intensity scenes on mid-range hardware, as long as you're using an Intel CPU. For some time around July 2016, it was unplayable on AMD CPUs. The developer managed to get it working pretty quickly, though.