Unlockable Equipment

Much of the best tech in Double Agent is available only as unlockable items. When you enter a mission, some of your objectives will be marked with a star. Completing the mission, while also completing the objective, will unlock a new weapon or piece of equipment for you, which will then automatically be added to your arsenal at the beginning of future missions, save for those that take place in the JBA headquarters.

Each star is worth one piece of equipment, and earning a star will unlock the next piece of equipment in the list. Since most missions have two stars, this means that, hypothetically speaking, if you beat mission one and earn one star, then beat mission two with two stars, you’ll unlock the first three pieces of equipment on the list. Going back and playing mission one again, and completing the second starred objective, will unlock the fourth piece of equipment, and so on. When you unlock equipment, it’ll be available for all missions, including the missions you’ve already played through.

EMP Grenade

Sticky cameras work well when dealing with distant enemies or enemies that you want to distract.

EMP Grenades effectively perform whatever action your EMP pistol would perform, but on multiple electronic devices in a small area. Not necessarily a game-breaking device, in other words, especially since you have an unlimited number of EMP charges on your pistol. It'll also be difficult to get these to affect high lights, which is where they'd come in most handy. With that said, the "explosion" of an EMP grenade is apparently inaudible to guards, so these are all but incapable of setting off an alarm on their own. If you chuck them towards an electronic object, guards will be attracted to the sound as they roll on the floor, then get doubly interested in the devices as they get shut off or otherwise go crazy.

Explosive Sticky Camera

The sticky camera is a bit more situational than other weapons in the SC-20k arsenal, and really isn't going to be necessary for most stealth-oriented characters; you can avoid most enemies in the game, and those you can't can be dispatched with shockers and airfoils much more easily than they can with cameras. That said, if you're on some insane quest to get through the game without ever attracting any attention or hurting a single opponent, then sticky cameras might be useful. When fired at a wall or flat surface, they'll impact and start relaying video data back to Sam, allowing him to see a good area around the camera's position. While in the camera view, you can use the alt-fire button to make a clicking sound, which will attract guards to the camera (and presumably away from Sam), while the primary fire will unleash a cloud of nerve gas that will incapacitate your foe. Unfortunately, the nerve gas firing is fairly noisy in and of itself, and will likely attract the attention of other nearby foes, which can cause problems if they find the body of the guy you just knocked out.

If you fire a sticky camera and don't use the gas feature, you can walk over to its location and pick it up to re-use it. Were this a purely first-person game, they'd thus be pretty useful for scouting around corners, but since you can simply adjust your view to peek around most obstacles, their utility as purely observational devices is fairly minimal, especially with your 3D map and radar functions.

Ultrasonic Emitter

The Ultrasonic Emitter will be a fairly handy device to have, especially in the many JBA HQ missions. When equipped, you can point it at a distant surface, pull the trigger, and it’ll emit a kind of barking sound at the point you aimed it at. This is great for trying to lure guards away from their routes or posts, and can also be used in an emergency if you’ve gotten the attention of a guard that’s slowly approaching your position. This is one of the best ways to "herd" guards away from you. If you simply keep moving the origin of the sound further and further away from you, you can put a guard so far away that you can sneak past the normal route that he’ll run.

Wall Mine - Stun

This upgrade to the normal wall mine will, instead of exploding, emit a cloud of knockout gas instead. Personally, we found the wall mines in Double Agent to be a bit buggy, where occasionally they simply won’t go off. The stunning wall mine also emits a fair amount of noise when set off, which is likely to bring other soldiers around, who’ll more often as not simply wake up the soldier that set the wall mine off.

Electronic Lockpick

The electronic lockpick is a useful upgrade, as it’ll simply eliminate the lockpicking minigame altogether and automate the process. That’s...all it does! But it’s still handy.

Gas Grenade

gas grenades work well when you have a lot of targets in close proximity to one another.

Gas grenades were featured in Chaos Theory as a launcher option for your SC-20k (and they’ll show up in the same form later on), but you also have the option to use them as simple hand grenades in Double Agent. Unfortunately, they’re pretty terrible in this form, since they make enough noise to alert guards near where they detonate, and the cloud of gas is usually small enough to only be useful in taking down one target, unless you can spot two soldiers that are standing directly next to each other. Generally, it’ll be better to separate your targets before finding some other way to take them down, but if you have one target that’s a good distance away from friends, then these can be used to disable them.

EMP Device - Enhanced

This upgrade simply reduces the cooldown time on your pistol’s EMP device. That’s pretty useful, though, especially if you have to maneuver through a well-lit area.