Here is the full list of all 13 Forge achievements.
Capture the relic 100 times
Heal team mates from 500,000 points of damage
Kill all bots on hard
Protect team mates from 50,000 points of damage
Deal 100,000 damage to enemies
Protect team mates from 5,000 points of damage
Heal team mates from 50,000 points of damage
Deal 10,000 damage to enemies
Claimed the first kill in a match
Kill all bots on medium
Kill all bots on easy
Complete the tutorial!
Capture the relic 5,000 times