The disagreements between TCR and FG regarding how challenging the game should be, both in terms of enemy encounters and in terms of puzzle-solving, resulted in the difficulty of the final game being much too easy. Once again, TCR should have been much firmer in defending the game that they wanted to develop, but they conceded too many alterations that resulted in much of the game's difficulty being suppressed. This impacted a number of scenarios in the game.
The Tunnels level was initially approximately four times the size of the version in the final game, consisting of more labyrinthine networks of corridors and claustrophobic rooms. Players had to retrieve chemical containers and use the vacuum tubes (present in the final game) to send them around the level and eventually back to the centrifuge. However, unlike in the final game, players were consistently hunted in this area by enemies, combining enemy threats with cognitive puzzle solving. The size and complexity of this area were eventually reduced drastically as the initial version did not meet FG's approval. While the intention of the original level was to emulate feelings of confusion, disorientation and of being lost without the frustration of actually being lost, FG felt that even these emulated feelings might result in player frustration.
The Bilge level also contained an additional area that combined puzzle-solving and enemy threats. The cogs required to repair the bilge pump (easily found in the final release of the game) were located at the end of a large, partially flooded room. Players had to navigate this area, avoiding a number of aggressive failed experiments in the water, retrieve the cog pieces and return (now burdened with the extra weight) to the machine. This sequence again did not meet FG's approval and was cut from the game.
Enemy encounters similarly were intended to be much less forgiving than they are in the final game. TCR implemented a system attached to a reworked version of the enemy AI. This system made use of a death counter already available in HPL2 to carry out different consequence sequences when players were "killed" by enemies. Rather than being killed and respawned at an arbitrary spawn point, players would be captured and respawned in a waste disposal area, or a specimen storage cage or similar area, separate to the main level. Players would then have to escape the area by solving a puzzle in order to return to the main area of the level in question. One such area can still be found in the final version of the game, located near the end of the Bilge level in which players must throw debris at a ladder in order to knock it down and climb out of the waste disposal pit. Furthermore, enemies would not disappear from the level. Each time the player was captured, enemies would either become slightly easier to avoid, or (if players were captured a lot by the same enemy) eventually despawn.
This approach to enemy encounters was felt to provide a good balance of challenge and tension whilst not becoming overly frustrating for players unable to get past particular enemies. However due to the lack of grey-boxing and of scheduling, along with difficulties in making changes to the AI system itself, the issues encountered during the implementation of these encounters could not be satisfactorily fixed before the game was handed over to FG. The result was FG reverting enemy encounters back to a state resembling much closer the behavior of The Dark Descent with enemies despawning if they successfully kill a player. This dramatically reduced both the difficulty of these encounters and the anxiety and fear that should have accompanied them. This is reflected in the critique of a both critics and players and is an area of the game that is far from the originally intended design.
