Enemy Unknown and Map Unseen
XCOM: Enemy Unknown is a highly renowned squad based tactical game mixed with base and resource management systems. I completed this game without any mods or DLC, so this review is based on just the game as it is today.
As an additional caveat, I should mention that I've never played a game in this genre before, so I don't really have a baseline to judge the game on, just how I felt after completing the game.
It took me three different attempts from the very start of the game to manage to beat it. My first attempt ended incredibly early on because I didn't have any real idea what I was doing. My second attempt lasted longer, but when I realized I had missed some important aspects of base management, I was already in a death spiral. My final attempt went much better and I ended the game only having lost 8 soldiers, but it required me to reload a few missions to prevent total failure.
I went into XCOM believing that it was the kind of game that wants you to push past failures since any single failure doesn't end your run. This was a massive mistake. The way that this game escalates in difficult makes it so that early mistakes can ruin your entire run. There are several systems that, when you're doing well, give you massive rewards, but when you make a minor mistake, they can prevent you from making any real headway. For example, you begin the game with a max squad size of 4 soldiers, but you can eventually increase that size to 6. 2 extra soldiers massivily increases your survivability, formation ability, and damage output, so it's one of the most important upgrades to get. This upgrade is locked behind having soldiers that have ranked up a certain amount, so if you don't keep your soldiers alive for about a dozen missions, with them consistently earning kills, you'll never get to increase your squad size, and you'll constantly be on the back foot.
There are other mechanics that have similar cascading effects where, if you are doing well, they make the game even easier, but if you do poorly you miss out on opportunities to get more power. Satellites are one of the MOST important mechanics in the game, and they seem to be tutorialized poorly as I didn't understand (any many other players don't understand) how important they are. When you put a satallite over a country, not only to do earn extra Money each month, but you also prevent that country from degrading further and eventually "pulling out" of the XCOM program, which really means they've been destroyed. If 8 countries leave, you lose the game. In addition to money, you also obtain scientists and engineers that allow you to research and develop more powerful technology, which leads to higher survival rates on missions.
XCOM is a delicate ecosystem of mechanics that feels a bit unbalanced. My first two attempts ended in abject failure that was so bad I had to reset the whole campeign. My third run, having learned what to prioritize and that losing too many characters is a recipe for failure, after the first few missions of success, but squad abilities began to snowball to the point where most missions were a cake walk (so long as I didn't make any boneheaded mistakes). So, this game highly rewards playing well and greatly penalizes failure, and it seems like there's not much balance to make the game harder for proficient players and easier for players not yet adjusted to the game.
All of this is to say that XCOM is a game that is ruthlessly difficult when you first start, but becomes increasingly easy as you come to understand how to play the game. I've seen many veteran players saying that this is an easy game, but I would say this is a very difficult game UNTIL you know what you're doing.
To try and make the game easier, you can lower the difficulty level, but I found that this lower difficult actually increases the difficulty in certain aspects. A major part of the game is resource management. To build structures, items, and defensive mechanisms, you need to have money and resources. The lowest difficulty changes 2 aspects of the game, you earn more money, and you face fewer threats. However, facing fewer threats leads to less resource gain, which means that it takes MUCH longer to gain more advanced technologies. Essentially, easy mode makes the game take longer to complete, but doesn't really address the underlying difficulty of managing your base, allies, soldiers, ect. You can still very easily enter a death spiral early on in easy, it just takes a lot longer to notice.
Having said all that, I did enjoy my time with the game, and I don't think it's a bad time, it just has a pretty massive learning curve, and you really can't afford many mistakes. If you want to take on a challenge and then overcome it in such a way that makes you feel incredibly powerful, XCOM does a fantastic job of that. If you're more interested in a good story, character development, or simply being able to relax, I'd avoid this game, and possible the whole series.
One final note, this game crashed my machine a few times, even though it's an old and not particularly demanding game. Adjusting the view settings often caused big problems, which is really annoying because you need to set the aspect ration to lower than most standard setups these days or you mouse cursor won't line up on the screen with what you're actually clicking on. So, try to adjust the settings once and don't touch them again.
