Summary
While playing games from start to finish is enough for many players, some will dedicate hours to seeing everything a game has to offer. Whether that’s completing the game on all its available difficulties, or hunting each and every one of its challenging achievements.
Sometimes, this pursuit of completion is just a matter of time, while others will require a certain amount of skill. The games in this list all offer something uniquely challenging, forcing players to master their mechanics if they wish to complete everything the game has to offer. Here arethe hardest games to complete to 100%.

Thissmash-hit indie Metroidvaniafeatures tough combat and an abundance of challenging bosses. Not only doesHollow Knighttake a while to complete, but its various achievements and optional content can be a real challenge.
Achievements like “Solace” and the infamous White Palace task players with some ridiculously challenging platforming in a game that’s arguably not built for it. Furthermore,many ofHollow Knight’sbosses, and extra challenges like the Colosseum of Fools, require players to master the game’s combat.

This wonderfullyretro pixel-art platformerfeatures plenty of platforming challenges and tough boss fights that make it a fun challenge from beginning to end. However,Shovel Knighthas plenty of achievements and extra content that make it difficult to complete to 100%.
Achievements such as “Impossible!” require players to finish the game without dying, while the achievement “Hurry Up!” tasks players with beating the game within one hour and thirty minutes. Furthermore, players will have to beat the game with each character, and beat the new game plus mode, to unlock all the achievements.

The Binding Of Isaacfeatures a ridiculous amount of content, even without its extensive DLCs, each of which makes the game even harder to 100% complete.The Binding Of Isaacis not onlya challenging rogue-like, making it difficult to beat in of itself, but its variety of achievements and alternate bosses make unlocking everything an arduous task.
The abundance of RNG present inThe Binding Of Isaacalso makes 100% completion all the more challengeing, prematurely ending runs that could have led to new unlocks. The large roster of playable characters, plethora of achievements, and challenging gameplay makeThe Binding Of Isaacdifficult to 100% complete.

Thisintense survival horror experienceperfectly captures the atmosphere of the originalAlienfilm, making it a great gamefor fans of the franchise. However,Alien Isolationcan be extremely challenging, in large part thanks to the invincible foe that constantly hunts the player: the Xenomorph.
Alien Isolation’sgameplay alone can be relatively challenging, especially for those that have little experience with the survival horror genre. However, it’s the game’s “One Shot” achievement that makes it so brutal, requiring the player to beat the game without dying.

TheDark Soulsgamesare notoriously difficult to complete, thanks to their variety of challenging boss fights and general lack of hand-holding that forces players to think for themselves. This focus on challenge and exploration is part of what makes theDark Soulsgames so special, but this also proves them tough games to 100% complete.
This is especially so withDark Souls 2, a divisive entry in theDark Soulsseries. This game features a variety of enemy ambushes and strange mechanics that make the game brutally difficult, including the loss of maximum health when dying. However, the lengths that players have to go to to find and kill the game’s secret bosses is arguably what makes it so hard to 100% complete, along with its tough-as-nails downloadable content.

XCOM: Enemy Unknownis a squad-based, turn-based tactics game that features challenging, strategic gameplay across a long campaign. Players are tasked with building and managing a base and their squad across a variety of missions, strategically upgrading their squad-members and base alike.
The challenge ofXCOMcomes not only from efficient management, but strategic gameplay on the battlefield. However, RNG can frequently mess players up, turning well-made plans into complete disasters if the dice don’t roll in their favor. Furthermore,XCOM: Enemy Unknownfeatures certain achievements that require mastery of the game, such as “Ain’t No Cavalry Comin'”, which requires players to have a soldier survive every mission of the game.

This rhythm-game rogue-like tasks players with playing to the beat at all times, fighting enemies that move and attack in rhythm.Crypt Of The NecroDanceris a fairly basic dungeon-crawler, but its this innovative twist that makes it so difficult.
Crypt Of The NecroDanceris a tough game to 100% complete, not only because of its challenging rogue-like gameplay, but because of its abundance of difficult achievements. In particular, beating the game with Aria, one of the game’s playable characters, is notoriously difficult. This is thanks to Aria’s own unique challenges, including starting with half a heart and not being able to gain HP. Furthermore, missing a beat while playing as Aria results in instant death.

This post-apocalyptic, traditional rogue-like features hardcore gameplay and a wacky, semi-procedural world full of possibilities. The game’s harsh rogue-like gameplay and abundance of unique mechanics offer heaps of emergent gameplay that makes hunting its various achievements a difficult task.
Caves Of Qudis a hard game with an expansive over-world packed with procedural caves and hidden locations. The game features so many interactions between items, NPCs, and just about everything, andCaves Of Qud’sultra-specific achievements acknowledge this. From contracting horrible diseases, to getting players to fall in love with themselves, there is an abundance of fun achievements to hunt inCaves Of Qudthat can take hours of play-time to unlock.