Complacent Gaming Syndrome: Both subverted and invoked. Invoked with the R-101C. It's the first primary weapon you have, which is just as good as most other automatic primary weapons. Same goes to the Chaingun for the Titan. Subverted as you regenerate note Think of Prestige in Call Of Duty as each Generation provides "Regen Requirements" which have to be met. They're essentially just challenges you already have available but has to be cleared to progress.
Game-Breaker: Early on in the beta, the "EVA-8 Shotgun" was considered this. By itself, it's an ordinary automatic Short-Range Shotgun that would not be out of place in any FPS games. But innate high movement speed of all pilots means that players can dodge gunfire, quickly close the distances and suddenly One-Hit Kill opponents. Extra breakage ensues if the pilot is augmented by the effects of the "Prosthetic Legs" Burn Cardnote Faster movement speed for pilots.
Suppressor attachments: like most First Person Shooters, a suppressor slightly reduces the damage and range of the firearm, but has the very useful benefit of not making the player appear on enemy radar when they fire their weapon.
A tactic that made saving your Titan for enemy evac worth it, may be getting scrapped as it was unintended by the developers: Titanfalling onto an evac ship. You're not supposed to be able to damage the ship with it, but it's possible and some people utilize it. Heck, most players thought it was part of Developers' Foresight and embraced it.
Play the Game, Skip the Story: The campaign is completely optional, but with how the campaign is a nice introduction to the proper game, or if you want all the achievements, it's not uncommon to see new players just jump straight to Classic Multiplayer.
Due to how the matching system works (it matches you on level, which is nice, but doesn't take generation into account), it means that completely new players will usually get creamed by more experienced players who jumped to campaign, to either get easy kills, or get achievements.
Polished Port: In a sense - Although the Xbox 360 version has lower framerate and visuals, it's impressive that it runs as well as it does in the first place, and is perfectly playable.
Rooting for the Empire: In spite of the IMC's Obviously Evil connotations, the faction has quite a few fans, partially because many players prefer their armor design over the militia's, and partially because of Spyglass.
It has also invitedsomecomparisons with Attack on Titan. Both series involve elite air-mobile soldiersnote With jetpacks for 3D Maneuver Gear fighting against giants called "Titans"note Mechanical rather than organic that have a weak point at the back of the "head" where they are "piloted".
The Enemy Chatter in the Fracture map for Militia grunts paints a pretty sad picture at the beginning of the story. Many of their families are onboard those ships, ships that, from the IMC side of the battle, are being deliberately targeted. When one grunt hears that the ship his wife and children were on just got shot down, and he's too busy fighting for his own life to mourn or worry about them.
That One Challenge: Previously, the Gooser challenge for Generation 5. You had to clear all 5 tiers (50 kills) by killing a Pilot ejecting from their Titan, which is harder than it sounds.* Mainly because most players stick to the Auto-Eject Kit which automatically ejects you and cloaks you too, making you completely invisible to Titans. Even then, it can be hard to kill one due to how fast they fall. Thankfully this was nerfed so each tier is one kill required, meaning that only 5 Gooser kills are required.
People who completed the challenge prior to the nerf are going to get rewarded by Respawn for their troubles, so it's all fair and square.
Getting Critical Hits with certain weapons: When a Titan is glowing red on certain parts, it's signifying a weak spot that you can hit for bonus damage. These Regen Requirement challenges have some weapons that are rather hard to use on certain Titans.
They Wasted a Perfectly Good Plot: It's pretty hard to pay attention to what's going on in the story when there's a thousand things exploding around the player and being shot at from every direction by hostile Grunts, Pilots, Spectres and Titans. Indeed, trying to follow the plot is a good way to drive your KDR into the toilet.