Here is the full list of all 24 HexTrains achievements.
Win 5% of all level versions.
Win 10% of all level versions.
Win 20% of all level versions.
Win 30% of all level versions.
Win 40% of all level versions.
Win 50% of all level versions.
Win 60% of all level versions.
Win 70% of all level versions.
Win 80% of all level versions.
Win 90% of all level versions.
Win 100% of all level versions.
Win 100% of all level versions with the highest rating.
Get 100 kills.
Get 500 kills.
Get 1000 kills.
Get 2000 kills.
Get 3000 kills.
Get 4000 kills.
Get 5000 kills.
Get 7500 kills.
Get 10000 kills.
Get 12500 kills.
Get 15000 kills.
Get 20000 kills.