Unfinished business is a great motivator. Also one of the main reasons for re-playing an old game that I played and loved in the past. I remember that I bought pirated copy of this game in a compilation CD along with AAA titles like Quake 2 and such, without ever played a ... tactical squad action game before. But the game was corrupted near the very end , and there was no torrents back then so I was forced to quit it.
Anyway, i now got another copy (also pirated :) and had another go. This game is released 1997 so I would not comment the graphics and the quality of textures, I can only say that if you're into that retro style graphics the visuals will appeal to you. At least, they won't be a distraction.
The game itself is said to have a lot of stuff inherited from X-Com (which I can't confirm since I haven't played it) which means that you manage a team of space marines pitted against an alien threat. The game is essentially consisted of 2 phases, team management and combat. In the team management well, you manage your team :) in short : you can buy/equip gear, apply earned experience into several categories and all that stuff, and you can use your team members in the combat situations that follow. It's very simple, yet very addicting combo. The combat mechanics is relatively easy to learn, especially since the concept has been copied and improved over and over (I had the same out-of-the-world locked-in-a-room experience with Jagged Alliance 2 afterwards)
The singe player game has a relatively short campaign (like around 5-6 hours) but the missions offer a great variety and each require different approaches to reach the goal (defend position, reach certain point, survive, kill a certain alien..) so it's packed with fun and in most situation moderate strategizing for succeeding the mission. That's actually what makes it a fun game. Viewing it as a puzzle game.
I think it's ungrateful to rate a game from 1997 fourteen years later, and I also can't really recommend anyone to play a game this old but it was as I said - unfinished business :)