* AntiClimaxBoss: The High Praetor isn't particularly difficult to actually kill once your Xenonauts are actually in range. Even the tricky issue of his psionics can be circumvented if you bring along the Hyperion hover tank, especially if you have a magnetic cannon mounted on it. The hard part is a) getting to him in the first place and b) escaping afterwards once the Reapers start swarming in.
* BrokenBase:
** Are the graphics unacceptably bland for a 2010s game, or is their plainness and simplicity the very thing that makes them appealing compared to the flash of ''VideoGame/XCOMEnemyUnknown''?
** Was it right to leave out [[spoiler:psionics]] and the Blaster Launcher?
*** Blaster Launcher still exists, albeit weighing a whooping 50kg, using an incredibly rare alien engine, and 500000$, making it unable to be used by anyone except soldiers in power armor with a huge bank account. And is useless. [[spoiler:Psionics]], however, [[spoiler:is a complete RedHerring]] that feels almost like a middle finger to people expecting it from ''X-COM''.
** Mechanical fidelity to the original is one of the selling points, but some think it's ''too'' faithful, WithThisHerring and all.
* DemonicSpiders: Reapers. They can move absurdly far, have a OneHitKill attack that creates another Reaper from its victim, and almost always come in large numbers. If you don't run them down quick on terror missions, you'll be facing a ZombieApocalypse in no time flat.
* GoddamnedBats: Light Drones don't do much damage with their plasma guns, but they are very good at suppressing your troops.
* GoodBadBugs: If you leave an injured soldier in your base to recuperate, it will take many days. However, sending him or her into battle again and using a simple medikit fixes the problem instantly.
** Now no longer in play as of v22 Experimental 5, as sending troops out wounded now caps their maximum HP during the fight.
** It used to be possible to have soldiers DualWield...''shields'', who could '''still''' throw grenades and smash aliens with kicks while doing so. Not a StoneWall to be laughed at.
* MemeticBadass: Josh Eales. Because of an [=RNG=] bug, this name was always in the starting party of every new game. Now he even has his own Steam card.
* ScrappyMechanic: Without mods, Mind Control has no cooldown and works instantly, meaning high-level Psionic aliens can just keep taking over your soldiers.
* TheyWastedAPerfectlyGoodPlot: The decision to tie the game's backstory into the UsefulNotes/ColdWar was an inspired design choice, and one that could have provided a justification for giving the player a more in-depth and nuanced "diplomacy" system where the player would have to tread carefully between two superpowers who, despite the imminent threat of alien invasion, are almost more paranoid of one another than they are of the aliens and would undoubtedly see the Xenonaut program as yet another prize to fight over for global prestige. Exactly none of this ends up being relevant to the game itself, however, which generally plays like a standard X-COM clone with a grim 1970's-era makeover. The sequel looks to be doing this, but time will tell how well it actually works.