He's tactically adept, brings energy, his passing is direct and crisp and offers good link up play. His positional sense and movement in the box is among the best in our team, his off the ball movement is good as well and his football intelligence is actually impressive, his spatial awareness is also good and he usually gets into good pockets of space.
Finally, he's a proven big game player but he's had a poor season like most of the squad. Mata hasn't been any better but is on a bigger salary and never gets slated much because he's a fan favorite. Lingard may not the most gifted footballer but these qualities are the reasons he displaced Depay and Di Maria for certain games. If Martial for instance had all these qualities he'd be twice the player because he's more talented.