Finishing the game's 12 levels was a frustratingly difficult task.

Tarpon are frustratingly difficult to hook because they have an extremely hard bony mouth.

It had been frustratingly difficult, he added, to determine the hostages' location with sufficient precision to carry out a rescue operation.

As in many games of its era, winning can be frustratingly difficult.

While this was more realistic, many players also found it frustratingly difficult, particularly in combat.

Panufnik had found it frustratingly difficult to get permission to travel to the States.

Features which are to be found in all, and only, the works of a particular author turn out to be frustratingly difficult to come by.

The producers of ergonomic computer keyboards and mice have found it frustratingly difficult to make major inroads.

He stares at me defiantly as if daring me to try to catch the fly - a task that is frustratingly difficult.

I found this in many ways remarkable performance of Daphnis frustratingly difficult to assess, even after several hearings.