If you are going to make an old-school adventure game it is important to still learn from the past. Having an open world is great but having what are obviously puzzles that you can't solve yet without the game giving a lead on what is next does not make for a fun experience. Combine this with the sometimes illogical aspect of the game (using radioactive substance for something it wouldn't actually work for or going through a dialogue tree to enter a number you already know) and (in my opinion) uninteresting characters and un-funny jokes and you end up with a tedious experience. LucasArts without the funniness and cleverness but with more of the frustrating illogical puzzles.
