The only one of the series I vaguely remember being somewhat difficult for my 10-year-old self.

played on the steam deck fun classic where the franchise all started

J'y ai joué tard , très répétitif

The first one is the best one probably.

This was my first Xbox 360 game when I owned my own Xbox 360 E in 2017 (not first 360 game ever). It's decent. You go to a location, climb the tower, kill the bad guy and then rinse and repeat like 10 times. The story is aight and the gameplay loop is fun if a bit dry. It's a good start for the franchise.