You don't have to play the first xcom game but it does help you understand the story if you do play the first one. If you look at the scores for the first game the second game Imo is even better. That isn't to say it doesn't have it's down falls. It does have slow load times the more you save games and the farther you get into the game. It is how they wrote the software so it's not a glitch it's just bad code and they can't rewrite the whole game just to fix it. So besides that it's one of the hardest and most fun strategy games I have ever played. If you like alien stories and turn base strategy games like final fantasy tactics but with realistic graphics then you will love this game. Also when one of your troops die that's it just like real life. They get wounded and die so be careful and have a blast.