Seriously, putting invisible hidden compartments in a wall is not making a puzzle. It's simply being an a-hole.
I don't know if it's supposed to be seen in smaller resolutions, but in full HD it's invisible.
Otherwise the puzzles were good, just fix that invisible compartment issue.
I normally love point-and-click games like this one, but the puzzles are so difficult. And for that book thing, you should at least be able to click the set, and it come up, not each one. Also, I finally found the code for the safe and was so excited, up until it didn't work. Please, I hope you make more games like this, but PLEASE keep the puzzles possible, because it' s way to hard.
Realised that the codes where a mix of modern and roman numerals very quickly. The first two safes where reasonably easy, even with the different possibilities presented with the roman numerals. But you have got me with the third. LXXI = 71 or 5021 or 6011 none of which worked. needs to be clearer what you mean. But apart from that good.
After unlocking the first two safes in less than a minute -- because you are given the combinations simply by looking at the walls behind each with the light turned off -- you are left with no clear clue as to what to do next, and no pattern to follow to arrive at the combination for the third safe.
The eighth page of the twenty-third book on the left book shelf contains "LXXI" which is 71 in roman numerals. The left bookshelf contains twenty-five books while the right contains ten, with each book containing ten total pages, but every combination of these numbers fails... in fact, upon trying all numbers which contain "71", which seems like the strongest hint, none work. Read upside down it could be interpreted as "1XX7" or "1207", which also does not work. Already it is clear that there is not enough information given to the player -- given the technique for solving the earlier safes -- to unambiguously have them figure out the answer without lots of guessing.
Viewing the safe interiors with the lights on yields:
3851049762
??????????
and again with the lights off:
__5___97_2
__3___14_2
Neither of these four digit numbers work as the combination, nor do their sum or their difference. It is unclear what significance -- if any -- is supposed to be interpreted from the highlighted digits being in the same positions. Also, there may or may not be significance to the fact that each digit is only used once in the first full number, or that the first full number is actually a cyclic permutation of the digits. Looking at the inverse as well as the powers of it taken as a permutation reveal nothing interesting or connected to the other numbers. Also, it seems like it may be prudent to figure out what the other six question marks are supposed to be, but not enough information is given to be conclusive.
I could go on and on like this, but I'll just leave it at this: After the "puzzles" the player faces immediately after starting -- which require no thought -- the player is faced with a puzzle that appears to follow no convention established within this game nor conventions common to games of this genre, and instead inundates the player with vague information which, when permuted and interpreted in all the different ways that might be reasonable, results in hundreds of plausible combinations for the solution to that puzzle. This is terrible puzzle design, and except for the trivial beginning, it breaks the rest of the game, so there's no way to say this game deserves better than one star.
ONE BOOK of the whole bookshelf contains "LXXI" written when u turn off the lights, you need to exactly click that book, that's ridiculous, you should be able to see it if you click the set of the book, not exactly that one in the middle of the pile.