These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
And then, there is one of the battlescape tracks - which is a cover of several of the level themes from Doom! Rip and Tear! Rip and Tear!
Scrappy Mechanic - Several things, like UFO hangers on-base and the current form of interceptions, have drawn fire from the fans and been marked for improvement.
On-base UFO hangars have been removed in the latest release.
And for people who liked the original X-Com, many don't like it when they can't save scum in battlescape since the developers feel it to be blasphemy. At least this time you don't have to worry about the One-Hit-Point Wonders of the original X-com since your early armor let you take a few hits. Also, you can still use wounded soldiers to fight.
In 2.3, UFO storage hangars have become off-base facilities.