We... look.... FABULOUS!
The feedback loop for this game is one of its smartest systems, because it encourages exactly the kind of behavior gives the player the best possible "Hitman" experience.
Players start with a single entrance point, and a single location they can smuggle an item into, along with some starter equipment. This gives them enough to successfully complete the level the first time (they could even do Silent Assassin if they are attentive enough, but that's unlikely).
But then, once they've completed the level, they gain experience in that level for the challenges completed on the way (and since killing the target the first time is it's own challenge, this is guaranteed). They go up in their "Mastery Level" for the stage, and gain new weapons/items, new starting locations, and new places they can smuggle equipment in through.
Knowing that more bonuses await, they are encouraged to replay the level, and find more unique kills and opportunities to complete challenges. This process is made easier both because they already know the level layout from having played it previously and by having new items and starting points to work with.
Then they complete new opportunities, gain more bonuses, and the loop continues on. Since Hitman is a series that thrives on players who love to explore and discover, encouraging this behavior through it's challenge/reward system gives the player the best possible chance of enjoying the game.
It's genius, and it's so bizarre to think that the genesis of these challenges is Hitman: Absolution, of all the games.