I've put quite a few hours into Gemini Rue so far. My opinion of the game seems to differ significantly from those from people I see around the web.
People are divided about the graphics - which is silly. The graphics are great. I have no problem with pixelated or "old-school" graphics done right, and these are really amazing.
My main complaint is that the game seems to exist mostly on nostalgia. It seems like it wants to remind me of games past, and impress me with its modern take. But that's completely different than actually giving me an atmosphere that sucks me in on its own. The game is by no means offensively bad - but I found many of the puzzles and the main story to be mostly predictable and tedious. The voice acting goes for cliche Alec Baldwin impressions over originality. Going through doors is tedious and inconsistent - sometimes you have to open and then awkwardly find the right place "beyond" the door to click to leave, and sometimes opening the door just lets you leave. Sometimes the door just opens for you. It seems like a small thing, but there are oh-so-many doors and it becomes an annoying design problem. I don't enjoy the apartment building settings, which all look the same, just tedious amounts of walking up and down stairs, etc.
Many of the puzzles in the "rehab center" became tedious. I have no desire to learn some intricate system of pipes etc. There's lots of tedium - and honestly, I'm not that driven to complete the story. I don't feel like I'm exploring a new place - at first, I got that exploratory buzz - but then you've seen the whole setting, and spend the next couple hours of gamplay revisiting the same places.... grey brown rooms after rooms...
The inventory can only be looked at by awkwardly right clicking ON an action object in the world... this seems weird, and no button to bring up inventory, at least that I can find in the menu. These kinds of design problems... seems like GR exists on nostalgia mostly.