If you are a fan of arcade shoot em' ups mixed with a bit of space sim, this is the best of the best in the genre.
I have 100s of hours in this from the physical CD version I had as a kid, and then the GOG version before it was released on steam.

My favorite game of ALL TIME, and one of THE BEST GAMES ever made, period.

The wonderful community over at Hard Light [hard-light.net] have worked hard to update the game's graphics to modern standards, do yourself a favor if you do want to play this;

Freespace Open Installer [www.fsoinstaller.com] <--- Go here and install the updated graphics, to play the game in full resolution, and even play 100s of custom modpacks made by some of the most dedicated fans of all time.

You wont regret it.