VANQUISH

You can melee attack robots while standing or boosting, and press when you're next to them. Sam will then perform a melee attack depending on the weapon that has been selected for combat. Different weapon combos will result in different melee attack moves!

Some examples provided by Solty:

• disc launcher : no AR used, and disc is fired at the end of the melee
• shotgun : hold for supercharged punch
• assault rifle : tap repeatedly for flurry of punches
• HMG : press + hold  to activate AR mode after the kick
• all weapons : boost with + press + hold to activate AR mode after the kick

Try melee attacks at least once with each and every weapon to see Sam's melee attack move to find the one you find most efficient. Be careful though, as every melee attack will make your ARS temperature gauge overheat, so get some cover after a melee attack. There is only one combo which won't make your AR Suit overheat, and that is when you've set the disc launcher as your main weapon.

As soon as you've destroyed 10 robots with melee attacks, you will unlock the "Going in for the Kill" achievement. Do this 90 more times and you will get the "A Heartbreaker and a Lifetaker" one as well. The melee attacks are cumulative across all playthroughs.

If you didn't get this achievement throughout the game, use level select after you've beaten the game and select Act 2-1 (River) on casual difficulty. You will start with a weapon crate at the very beginning. Kick it open. If it's the disc launcher, pick it up and let yourself get killed, then choose "checkpoint". That way, you can reload the last checkpoint over and over again, and have the disc launcher right from the start. You can also pick up the sniper rifle which is always there in a drop pod. I found that doing melee attacks with the sniper rifle equipped, I could kick multiple robots with a single melee attack. Anyways, boost under the truck and perform as many melee attacks as you can. Then, press and choose "checkpoint". Rinse and repeat until you get the achievement.