Nothing like it, before or after.
To get these flaws out of the way, they are two-fold. One, the game is difficult, and the aliens have a tendency to annihilate entire squads with a lucky shot of a blaster-bomb. The balance of the game does allow veterans to give themselves the edge however. The second flaw is that the interface is somewhat non-user-friendly, but you have to expect that with older games.
And what does this game do right? Just about everything! The basic premise, building bases, shooting down UFOs and clearing the crash-sites, and later on, alien bases, provides itself with all the gameplay you need. The reverse-engineering of alien technology gives you a nice progression, from completely outmatched, to power-suited monsters.
The strategic map, where most of the action takes place, is a bit hard to get used to, but the action, despite being turn-based is *very* tense. A stray shot can kill any of your troopers. As well, unused Time Units allow the aliens to shoot you even in your own turn, though you can do the same!
The best part of this game is the environment. The music is creepy. The environments become all too scary as aliens shoot from the rooftops, or rush out of corners to hit you then run back behind them before you can hit them back. The sounds just reinforce this effect.
All-in-all, a masterpiece, if you just put in a little effort to learn its system. Highly recommended.