Serious Sam 4
54 Achievements
15-20h
GOG
Roman Holiday
Get together with your friends and kill something big.
41.6%
How to unlock the Roman Holiday achievement in Serious Sam 4 - Definitive Guide
This achievement will pop upon completing the mission "Death from below". To make this easier make sure you have infinite ammo turned on and even tourism difficulty or play on co-op and set respawn timer to 0.