Sniper Elite VR works cumulatively. In order to progress to each level, you need to earn a target number of stars. If you have not reached this total, the next mission screen will tell you how many you need.
How do I earn stars?
Each level has objective which are worth a star each. These objectives appear at the end of a mission.
If you have not reached the total number of stars required, go back to previous missions and complete objectives you haven't before.
If you are still having trouble, please get in touch via our Contact Form.