Tips and Strategies
Shoot the barrels
Throughout the stages, you will see explosive barrels scattered around. Try and lure your enemies near it, then shoot it. It will deal massive area damage and take out most of your enemies.
Need more ammo?
Look out for blue crates on the ground. They are quite small, so they are easy to miss, especially when you're running around trying to get away from enemy gunfire. Picking them up will give you 60 ammo, so until you find one, your shotgun's your best friend.
How to refill health?
Purple canisters are health refills. Taking one regenerates about 25 health. You may want to save these up though, as it is very likely to face opposition by the time you need to run back to the elevator.
Keep your enemies close
Every enemy unit has their own distinct movement and attack patterns. It is up to you to learn them and exploit the weaknesses they have in order to dispatch them cleanly. If you master their patterns then you'll be able to save a lot of health and ammo and will progress in the game further. This will also improve your performance rating, thus improving your rank as well.
Who let the dogs out?
These little dog robots can be quite annoying, as they continously shock you if you get into contact with them. However they're quite fragile, as you'll be able to take them out with one clean shot with your shotgun.
Shoot 'em down!
Flying robots are hard to aim and shoot at, so it would be best to have your auto-aim on. This will allow you to target them with precision and take clean shots at them, thus saving you energy and ammo. Less pesky things too.
Take the turrets out
These turrets have laser sights, and once they set their sights on you they will open fire without hesitation. Avoid these lasers by moving continously. Target them and take them out with a few shots with your shotgun.
Destroy the sentry
These sentry units are harder to kill than your average robots. They're tougher and stronger, however they have a lot of openings that you can take advantage of. Before sentries fire pulse lasers from their chests, they tend to stop for a short time. Use this chance and use your grenade launcher to take it out. At best, the blast from one shot will take it out. If not, then two.
Save up on extra stuff
Don't take everything if you don't need them. For example, if your health is full, then don't take the purple canisters. You bring your current health to the next stage and it does not get replenished, so it would be very wise to leave those canisters alone unless you really need them. The same goes with ammo.
Take your time
Faster isn't always better. Take your time to finish off all the enemies and don't just head off to the elevator, since this is one factor that will affect your ranking. Also, try and take enemies out quickly and consecutively to perform combos which also adds to your ranking.
