The first one always seemed to me like IO Interactive really wanted to break through with this amazing new idea of the Hitman gameplay, but since it was quite different from the usual games, IO was afraid it would fail. They then put way too many forced action scenes into the game to try to appeal to more people when it should have been a stealthy game the franchise is now known for.
There is a reason why Contracts is full of missions from the first game, IO saw their mistakes and wanted the missions to be experienced the real Hitman way.
So yeah, the first one is definitely the worst, but Absolution is by far the most disappointing after Blood Money, one of my favorite games of all time, was released.
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