Close, but no cigar
I'd like to start off by saying that personally I don't have any moral qualms regarding this game, despite the somewhat negative buzz around this "murder simulator" as some have called. I'd also add that, as far as I recall, the game doesn't reward you for killing civilians or police officers. In fact it penalizes you for it.
As far as the game itself is presented, the graphics are good for its time, though not entirely consistent. Some things look better than others. The sound is decent overall, though the voice acting is pretty dreary.
The levels themselves are well thought out, for the most part. Unfortunately (or perhaps fortunately... more on this below) most levels aren't exactly long. Despite the fact that, as a hitman, you'll be expected to kill your targets, the gameplay rewards being able to accomplish the task with as few "incidents" as possible. Any sort of extended firefight is counterproductive in this game.
The AI is also good: civilians will alert guards if the see something suspicious, enemies will react to gunshots, or to dead bodies, they'll call for backup etc.
The downside of this game is what also pretty much ruined my enjoyment of the game: there are no saves in this game during missions. Not even checkpoints! You go in, you screw up... you start over. Imagine playing through a relatively long level and making a mistake at the end and having to repeat the whole thing... that to me is frustrating. I'm sure there are some gamers out there that enjoy this sort of challenge, but to me the game quickly becomes an exercise in tediousness and repetitiousness. It's not a good sign when you start hoping that the next level will be a short one.
The problem is compounded by the control scheme and the inventory system. The game treats walking and running as two different things; in most games you use a key to alternate between walking and running. In H:C47 there are two separate keys for walk/run. So if you're walking and you want to run, you must first release the walk button and then switch to the run button.
Worse than this is the inventory system which uses scrolling exclusively. There are no hotkeys for different weapons/items. This makes access to your inventory both slow and imprecise. You can get used to it, but it's still a bad system in a game where you have to be quick to react.
Other than this, I can't thing of anything that is really wrong about the game. Sure, the story is nothing special, but I don't think that in a game like this it's that important.
The Bottom Line
Ultimately this game could've been a really good one, if it wasn't for the absence of saves during missions and if the controls would have been better.
If you can look beyond these two problems, there's a good game underneath. If you can't, you'll just probably quickly get frustrated with it.