Here is the full list of all 39 Armor Blitz Playtest achievements.
Complete 1 mission
Complete 5 missions
Play 1 multiplayer match
Win 1 multiplayer match
Destroy 1 enemy using the Charge Shot
Complete 10 missions
Play 5 multiplayer matches
Destroy 1 enemy with the C4 explosive
Destroy 1 enemy using the Flamethrower
Destroy 5 enemies with the Laser Beam
Destroy 10 enemies using the Ricochet Shot
Destroy 10 enemies using the Grenade Launcher
Destroy 10 enemies using the Guided Missiles
Destroy 1 enemy using the AT Mines
Destroy 5 enemies using the Spread Shot
Use 5 Stun grenades
Pick up 5 Armor Boosts
Pick up 10 Health Boosts
Pick up 5 Speed Boosts
Pick up 5 Damage Boosts
Pick up 5 Rapid Fire boosts
Pick up 5 Reflective Shield Boosts
Pick up 10 Invulnerability Boosts
Pick up 20 Explosive Shells
Pick up 5 Quick Charge Boosts
Pick up 50 Weapons from crates.
Complete 15 missions
Complete 18 missions
Play 10 multiplayer matches
Play 20 multiplayer matches
Play 30 multiplayer matches
Win 5 multiplayer matches
Win 10 multiplayer matches
Win 25 multiplayer matches
Win 50 multiplayer matches
Win 5 matches of Deathmatch
Play 5 matches with a team of friends
Win 5 matches without being hit
Win 100 matches vs other players.