There are many potential timesaves here:

1. the horrible G2 and G3 fights
2. pick up less ammo/herbs/fas/upgrades/flamethrower
3. memorize the route/puzzle solutions so I don't have to look them up
4. shoot less, dodge more
5. learn to consistenly dodge enemies in the first place, esp. Mr. Kill
6. use mouse/keyboard instead XB1 controller (as flicking those loose sticks will cause unwanted inputs)