Here is the full list of all 87 I, Gladiator achievements.
Defeat Cathbad the Druid
Defeat Biork the Berserker
Defeat Kolhid the Monster
Defeat Spiculus armed
Defeat Spiculus unarmed
Reach 5th level
Reach 10th level
Reach 25th level
Reach 50th level
Impale 5 opponents on spikes
Impale 25 opponents on spikes
Impale 50 opponents on spikes
Send 5 opponents into 'Bond Of Rivals' trap
Send 25 opponents into 'Bond Of Rivals' trap
Send 50 opponents into 'Bond of Rivals' trap
Hit 5 opponents when they are foot trapped
Hit 25 opponents when they are foot trapped
Hit 50 opponents when they are foot trapped
Fry 5 opponents in 'The Fire Of Faith'
Fry 25 opponents in 'The Fire Of Faith'
Fry 50 opponents in 'The Dire Of Daith'
Dismember 5 opponents with the 'Iron Vortex'
Dismember 25 opponents with the 'Iron Vortex'
Dismember 50 opponents with the 'Iron Vortex'
Kill 20 opponents
Kill 100 opponents
Kill 500 opponents
Perform a 10 hit combo
Perform a 13 hit combo
Perform a 16 hit combo
Destroy 5 totems
Destroy 20 totems
Destroy 50 totems
Kill a lion
Kill 3 lions
Kill 10 lions
Enter the fight with no weapon and win
Use 20 different types of weapon
Shed blood of 30 different opponents with a sword
Stun 30 different opponents with a mace
Go through the block 30 times
Kill an enemy with the weapon of the other defeated enemy
Kill an enemy with the weapon thrown by spectators
Dismember 5 opponents entrapped in 'Bond Of Rivals'
Dismember 50 opponents entrapped in 'Bond Of Rivals'
Dismember 200 opponents entrapped in 'Bond Of Rivals'
Dismember 5 enemies in a row
Kill an enemy without receiving any damage
During one fight kill three opponents with three different traps
Kill three enemies within less than 40 seconds
Kill four enemies within less than 30 seconds
Dismember two persons with one blow
Dismember three persons with one blow
Play IG every day for a week
Play IG every day for a month
Shed 10 litres of blood in the arena
Shed 100 litres of blood in the arena
Shed 1000 litres of blood in the arena
Burn 500 kilocalories
Burn 5000 kilocalories
Burn 50000 kilocalories
Run 5 kilometres
Run 25 kilometres
Run 100 kilometres
Drive 100 spectators to the tears of happiness
Drive 300 spectators to the tears of happiness
Drive 1000 spectators to the tears of happiness
Win in the arena, hitting nobody
Dodge lion's attack 50 times
Being knocked down 20 times
Being knocked down 50 times
Being knocked down 100 times
Lose 5 times in a row
Lose 10 times in a row
Lose 15 times in a row
Count 100 stars
Count 250 stars
Count 500 stars
Buy all helmets and armor
Win for the first time in the Pugnator
Win for the first time in the Insequitur with other gladiators
Win for the first time in the Exterminator
Win for the first time in the Insequitur with totems
Complete all 3 laurel challenges in one fight
Complete 10 laurel challenges
Complete 100 laurel challenges
Complete 240 laurel challenges