I think a lot of negative reviews might be comparing TTP2 to Road to Ghennea. The latter is a DLC that greatly improved and expanded on the base game. And it is unfair as the base TTP1 itself was way less challenging and well made than what those people seem to remember. TTP1 base game, in my opinion actually was less challenging than TTP2. The puzzles were mostly well contained boxes. As for the stars, remember that you even had one hidden behind a fake wall that I think was disappearing after you'd pulled a lever hidden behind some palm tree, or something similarly dumb.

TTP2 introduces a lot a good mechanics, eliminates puzzles requiring some form of timing - which doesn't make for good puzzles, especially when the difficulty of these relies mostly on getting the timing right. You can certainly expect those mechanics to be expanded upon in a DLC that will be to TTP2 what Road to Ghennea was to TTP1.