Alien Breed 2: Assault

Missable
The earliest you can unlock this trophy is in Level 3. You only need to hit the aliens with a melee attack, not kill them. Here they are in the order you should encounter them.

Level 1
Larval - These are small aliens that crawl on the ground and jump at you. Just to be on the safe side you should melee attack one of their pods that they hatch out of.
Mauler - This is the standard alien soldier. They look like the bug aliens out of the movie 'Starship Troopers'.
Healer- This guy looks like a really big bug with four legs. The underside of its tail is bright yellow. It heals other aliens with a bright yellow beam.

Level 2
Screamer- This alien is similar to the Mauler but its head is much larger. It will scream at you before charging.
Stunner- This alien looks like a smaller version of a Healer except for they give off a purple color when they attack or you shoot it. They will make a small explosion when getting close to you. This will hurt you and slow down time for a short period.
Ranged- These guys look like big scorpions and they have bright green eyes. They shoot small green projectiles at you.
Bone Shield- This is one of the larger aliens. This guy will either use its arms as a shield or shoot yellow balls of energy at you that explode.

Level 3
Webber - The last alien you need to melee hit looks like a big lizard. Its torso is blue and it will fire projectiles at you that make you walk slowly like you're stuck in a web.

The 2 'boss fight' aliens don't count.