This is a very clean port of a classic BASIC game that's been around since at least '79. (That's when my earliest copy is dated.)
In 'Star Trek', you are in command of the Enterprise (duh :) during a 30-day mission to rid the galaxy of Klingon invaders. The game is turn-based, and during each turn you manage most of the functions of the Enterprise, by allocating energy to shields and phasers, aiming and firing Photon torpedoes, monitoring Damage Control, or requesting area scans. The galaxy around you is divided into an 8x8 grid of quadrants, which are subdivided into 8x8 grids of sectors. Long- and Short-Range Scanners enable you to search for enemies to fight, or starbases to repair and refuel your ship.
Mark has made good use of the function keys, using them to select the various functions of the ship, and freeing up screen space for the map and status display. In the original, these were all three-letter commands to be typed in each turn, and if using the ship's computer, another number command to remember.
The graphics in this version are as good as the original, with the addition of a graphic title page that looks a lot better than the early one.
For me, the game has obvious replayability, it didn't last this long by being boring. It requires you to use your head, and not just your thumbs, to succeed.