How many puzzles are at the talos principle?

How many puzzles are at the talos principle? I mean how many "tetris-pieces" and stars one can/need to collect? Are there other type of puzzles?

I would like to know the size of this game before buying it. I don't need an exact number, estimation within +/-50% is good enough.

Solution 1:

I almost completed the game and now I have quite good estimation of number of puzzle it has. There are:

1. Exactly 99 sigils puzzles: 18 green + 23 yellow + 49 red + 9 grey.
2. At least 30 star puzzles (some of them are not really puzzles, but exploration tasks). May be more, but I don't thinks so, since exactly 30 stars are needed for 3 doors and currently I know exactly 30 stars locations.
3. Exactly 6 puzzles at the tower.
4. Exactly 3 messengers puzzles. But those are extremely simple.
5. At least 39 easter eggs, these usually also don't require a puzzle solving, but exploration.

In total this would be 138 puzzles + 39 eggs, may be few more eggs.

P.S. New DLC: "Road to Gehenna" additionally provides 24 very good sigil-like puzzles + 16 star-like puzzles + several eggs.

Solution 2:

There are about 130 pieces in the game. I don't have exact estimates for the amounts of the first two types (green and yellow; easy and medium difficulty, respectively, and used to unlock new areas and new puzzle mechanics, respectively), but I'm fairly sure there are about 20 green and 30 yellow pieces. There are exactly 49 red pieces (difficult, can be used to unlock the second ending and part of the third ending or simply collected to get the first ending), 30 stars (found all over the maps, often in hard to reach areas, and used to unlock the silver piece maps), and 9 silver pieces (difficult to very difficult, used to unlock the third ending).

Additionally, three extra stars can be acquired by redeeming reward codes from the free "Sigils of Elohim" game. You can also unlock three puzzle hints from this game in addition to the three you can get in the game, but each hint can only be used once and they can only be used in the red piece puzzles.