Adventure games exist on a spectrum from what are essentially puzzle games with characters (such as Zack and Wiki and possibly Professor Layton and the Mysterious Village) to games with little interaction that are basically interactive books (I would include an example here, but, at risk of blowing the punchline, the game I am reviewing is further on this side of the spectrum than anything else I have ever played). The interactivity in Time Hollow consists mostly of moving from area to area. Once you find the right location (park, school, home) events frequently set themselves in motion and you just have to tap the screen to advance the dialogue; sometimes you have to tap each character on screen to get him or her to speak.
There are a handful of objects in the game which are very obviously interactive, so finding them and their application is rarely a challenge (the plus side of this is that it means there is no pixel hunting). The most interesting and versatile of these objects, and the one from which the game takes half of its name, is the Hollow Pen, which allows the protagonist, Ethan, to open a hole in time and interact with some very specific moment from the past. This mechanic is the driving force of both the plot and the gameplay (such as it is).
While this is potentially a very interesting way to interact with the world, its use in this game is somewhat proscribed. Use of the pen does frequently result in unintended consequences (saving the life of one character results in the death of another), but they are normally very direct; your actions do not change only the event you are trying to impact, but the sphere of influence usually extends only one or two consequences away. There is no butterfly effect at work here.
Since the lack of gameplay means that the game is mostly plot, we shall judge it on that plot. The game starts off well, introducing Ethan and several of those who will remain the main characters throughout the story in such a way that we get to know their personalities and how they interact with each other in advance of the conflicts in the game. Once the action starts to pick up, since we know these people moderately well, we also know where to look for them and how they are likely responding to whatever new crisis has just erupted. It is a testament to the game that when I would find a character after opening a time hole that altered his past in such a way that his personality has changed, I would think to myself “How unlike Character X to behave that way.”
A mildly strange effect of the parallel histories is that our hero does not know his own past. He is as clueless as the player. From a gameplay standpoint this makes sense; if the character knew everything that had changed, he would not have to seek out information and we would never have any idea what is happening. From a logical perspective it is a little more difficult to justify. Even though Ethan ostensibly lived through the period (his friends certainly seem to think so) between the change and the present, he knows nothing about it.
Unfortunately, once the game moves into its later stages (conflict and climax) the creators seem to have written themselves into a corner and relied on the fact that the Hollow Pen is mysterious to resolve any outstanding issues. Several late moments consist of a character suggesting doing something novel with a time hole or the Hollow Pen and hoping against hope it would have some effect despite our having little reason to believe it would. Of course, it works and the story progresses.
Time Hollow moves briskly because of its lack of difficulty and focus on plot, and is compelling despite the flaws in its storytelling. While I would like to see several of the characters appear in any future installments of the game, I hope the developers would be a little more creative in their use of what could be a great mechanic.