XCOM: Enemy Unknown is not a particularly easy game, even on the mode that is literally called "Easy." 2K has announced it will address this in an upcoming patch, along with various other bug fixes. It didn't detail exactly how the game will be made easier, but presumably it has something to do with making fewer of the aliens big stupid jerks.
The patch notes (via PC Gamer) also promise fixes to hanging issues during Interceptor sequences and AI alien activity, Abductor roof visibility problems, SHIV inaccessibility, and multiplayer connectivity. You'll also find that the TempleShip doesn't mess up your spawns, and the Snapshot penalty won't apply anymore when Overwatching without moving first.
The post also notes that Firaxis is looking into the issue that causes a defeat screen despite finishing the game, but it's careful to note that this is early and not confirmed to be fixed in this patch. The second patch, with all of those other fixes in tow, hasn't set a date yet.