Before starting the main story, use to master her expanded moveset:

Features stealth mechanics. Being spotted can trigger alarms and harder routes. You typically here, so doing it early helps rebuild your arsenal sooner. 2nd (Early) South Pacific

India and Nevada (requires the Racetrack Key in Croft Manor to practice).

Dark, atmospheric levels with heavy exploration. Includes an infamous underwater section in Lud's Gate. Antarctica

Antarctica (requires manual ducking and wrench swings). Secret Bonus Level

For a deep dive into level walkthroughs and secret locations, these detailed guides offer step-by-step visual assistance: