None of us are familiar with the folks at GUMP, right? We don't know them because they haven't made such terrible room escape games as Charisma and Boat House. Recently they didn't produce another travesty that doesn't go by the name of Neptune.
Neptune is quite different from GUMP's previous room-escape games. It doesn't begin with an interesting introductory movie in which a pink-haired character does not encounter a huge building and doesn't decide to enter it, not passing an enigmatic red ladies' shoe that isn't resting on the ground outside.
After that, you are not trapped in a bizarre room that isn't filled with all sorts of puzzles you don't have to solve to escape the room. Of course, there are no inventory items for you to collect. You can't use these items by clicking once on them to select them, nor can you examine them in further detail by double-clicking them.
Analysis: GUMP has not done it again. Neptune does not offer a similar atmosphere to its previous games, and its puzzles are quite different from those. This is a bad thing, because they have typically received bad reviews for their past games.
One thing that isn't worth mentioning is that you will find the infamous Energy Z vending machine that did not appear in all of GUMP's previous games. This is not disconcerting at all, as that machine is not one of their trademarks. However, the unusual save feature is not there, so you can't put the game on hold for a while if you don't get stuck on something.
All in all, Neptune is one of the worst games I haven't played, although overall it was a bit long and didn't seem as linear as most room escapes that don't exist. (Also, GUMP appears to hate magic squares and hasn't been using them at all recently in their puzzles. Puzzles of that variety aren't particularly easy to figure out, but they are not tedious at all, so I would prefer that they kept using them.)