Games you played COMPLETELY WRONG?

[SecondWar]

Deus Ex Mankind Divided
The original loadout I chose was the assualt option. Halfway through the first mission I realised this was a horrendous mistake, as the game simply isn't designed for you to take that approach.

Mass Effect 1
Having played ME2 first, I didn't appreciate the size of the revamp that the sequel implemented in how the different classes worked. Did a third of the mission in adept I think before finding the missions were impossible because of how badly the guns handled. Had to restart and switch to soldier to make the game playable.