The primarily reason one would want to play this genre of games is the puzzles, so let's quickly cover everything else to get them out of the way so we can focus on the puzzles.
The graphics are a little above average for an indie game, though nothing spectacular. The environments are interesting, although a little on the noisy side which can make it difficult to tell when something is supposed to be interactable versus just decoration. The music is sufficient for the job, but nothing remarkable. The story is about average for this genre, a backdrop provided to barely provide motivation, but generally not worth paying attention to.
Again, none of this is all that important, and a game can still be range anywhere from terrible to fantastic despite all of the above, depending on the puzzles.
Unfortunately, In The Space Escape Room (ITSER)'s puzzle design is often very lacking.
A lot of the puzzles involve giving you some visual cue (often just somes numbers), and then asking you to guess the answer, which is itself a sequence of numbers. For example, you might be given the clue "3827" and now your job is to guess the answer, which is itself a four digit number.
There simply isn't enough information to figure out the answer. There's lots of different four digit numbers you could derive from 3827, for example 5535, or 5753, or 1946, and so on, and they are all reasonable, with no indication of why one transformation might be preferred over another. And so a lot of these "puzzles" are just trying the standard set of number-transformations that frequently get used in puzzle games, and seeing which one the developer happened to use for this particular puzzle. "Are they doing the thing where you look at [spoiler]the number of letters in the English spelling of the number[/spoiler]? No? Okay, are they doing the thing where you look at [spoiler]how many straight lines are needed to write the number down using a standard LED style font[/spoiler]? Are they doing the thing where each number represents a [spoiler]day of the week and I have to translate the the English spelling of that day of the week[/spoiler]?"
ITSER also reuses the same types of puzzles repeatedly, which feels like it's just padding out content. For example, there are multiple copies of the "sliding 15 tiles" puzzle; there are multiple copies of the "rotate titles to form a path" puzzle; and there are multiple copies of the "lights off" puzzle. The puzzles don't gradually get more difficult or have any variants thrown into them or anything. Once you've solved one of them, it feels tedious to solve another instance of them. (And in fact, these puzzles tend to be so overused in puzzle games that even the first time you encounter them in a game, there's already a sense of tedium). The "lights off" puzzles in particular, seemed to be designed in a very lazy way: Many of the switches that you can toggle don't affect any of the other switches, and so getting all the switches into the on position is often very trivial.
There are also a couple of logic puzzles, like "Alice likes apples. The person who likes bananas is not Bob. Charlie is to the left of the person with the cat. etc.". However, they also seemed to have been poorly designed, often allowing for multiple solutions. Unfortunately, the game only accepts one of those solutions, so you'll sometimes find yourself devising a solution which the game simply does not accept, and you simply have to try to find a different solution that also satisfies all the statements provided in the puzzle.
The one puzzle that stood out to me as well designed was the one where a girl had to grab a knife and get to the exit without being spotted. There are plenty of "find a path satisfying a constraint" puzzles out there (see, for example, The Witness), but this was the only one present in ITSER, and so it felt "fresh" in comparison to the other puzzles that the game made you play through. It was also one of the few puzzles that you could solve completely on paper independently of the game, and be confident that your solution was correct before entering the solution into the game (in contrast to those "Guess what transformation I'm applying to these numbers" puzzles).
Overall, I found this game more frustrating than entertaining. If you're a fan of the genre, I would recommend instead looking at The Room series of games.
