Very rewarding puzzle game with puzzles that are creatively designed. Stick to it and you'll have a great time.
The main character, you, has to find a will in the big mansion of a safe cracker fanatic. The will isn't readily available, you'll have to solve puzzles to get from room to room closer to the last room with the will.
The puzzles range from medium to difficult, and I definitely needed some help from a walk through, but I solved 90% of the puzzles myself by just sticking to it. I found a nice walk through that offered hints before giving the whole solution. There are some cliche puzzles but over all they are definitely creative. They all have a little bit of "steam punk" feeling going. Victorian Technology.
The puzzles always reset when you stop, so you can't mess anything up. just messing about will usually teach you the logic of how it works, then you can reset it and figure out how to get to the desired end result. Keeping pen & paper close by is recommended and will make solving the puzzles a lot easier and less cumbersome.
The graphics are nice, they are kind of Myst style. Nicely rendered but it's not really 3d, walking around from puzzle to puzzle can be a little slow at times.
So if you're looking something a little more challenging than sudoku-level puzzles, but nothing too crazy difficult, this could be it for you.