When Arok makes it out of the cavern, he is faced with more fundamental challenges, such as finding food to satisfy his growling stomach, gaining the trust of people who can help him, and making a bridge to cross the rushing river. This section is less mystical and more realistic, but the challenges—primarily inventory-based—are still enjoyable. The inventory can be a little awkward, however. You can't use one object on another within the inventory bar, which means an item must be put down somewhere before it can be combined with another item. But you can only place an item where the game lets you, as indicated by an animated cursor. As a result, I sometimes thought I couldn't use two items together, when in fact I just hadn't moused over the spot where the game wanted me to put the first of them down. It can also sometimes be hard to tell when an item in the environment can be picked up. The cursor animates when you put it over an object that can be taken, but even so, I missed a few things during my first (and even second) sweep through the screens.

There are a couple of painting-related puzzles in this middle part of the game, when Arok is tasked with restoring a fresco to prove he is worthy of meeting Klem. This is the first point where Arok really gets to paint, by finding the proper supplies and using them correctly on the wall. Like the other puzzles in the valley, it's a mechanical experience—you're mixing pigment and physically spreading it across the wall—and it serves as a nice transition to the third part of the game, which takes place at Lascaux.

Once Arok reaches Lascaux and gets in to see Klem, he is asked to fill the chamber with bulls and to get them to dance. The mystical element returns as puzzles again become a form of communication between Arok and the cave. However, some of these puzzles felt like busywork to me. The worst offender is a sort of slider puzzle that's significantly more difficult than the rest of the game's challenges. It's also the only point in the game when Arok is supposed to be painting, but you (the player) are forced to solve a puzzle instead. This took me out of the game, because even though I knew exactly what the fresco was supposed to look like, I just couldn't manipulate the slider to get it to look that way. This is not a challenge Arok, as the painter, would have to face. It didn't help that when I saved my game with the puzzle nearly complete, then reloaded it, the slider was reset—even though the screenshot on the save menu showed the puzzle nearly complete. Alt-Tabbing away from the puzzle caused it to reset, too. After well over two hours of frustration, this annoyance, plus the puzzle's mechanics (much harder to manipulate than the average slider), sent me to a walkthrough. Indeed, this was supposed to be Arok's hardest challenge—completing a fresco that not even Klem had been able to paint—but I would have preferred a less contrived method.

Although ECHO's prehistoric setting and premise score points for originality, the plot is straightforward and extremely singular. Arok wants to find Klem's cave and become a painter. That's about it. Along the way, nothing that happens is really surprising. Arok never misses the clan he left behind, never doubts his abilities, is never tempted to give up his quest or forced to choose between two paths. Some players may not mind this simplicity, but the absence of a deeper layer of storytelling left me disappointed. It wouldn't have to be complicated—even an implied love interest between Arok and Tika, the game's only female character, could have done the trick—anything to add a bit of tension from within and balance the external obstacles. That's not to say that ECHO's story is bad; it's just simple. The plot is well constructed and obviously well researched, but it lacks the complexity and character development I expected a coming-of-age tale to be infused with. I'll admit, though, that I have high standards when it comes to story. For those who prefer games with more puzzling and less plot, ECHO may have just the right balance.

In spite of these faults, ECHO is a quality game. The puzzle-heavy first-person adventure has become something of a cliché, but with the prehistoric setting and emphasis on cave painting, ECHO puts a new spin on that old convention. In fact, the complaint I expect to hear from many players is that the game is just too short. I felt that way myself, even after the two-hour slider debacle. The game took me just a few evenings to play, and the puzzles were easy enough that I really only got stuck once. When a game is as nicely put together as this one is, I want it to be at least twice as long. I guess that's to be expected of an echo, though. Even after it has faded into silence, you strain to hear just one more repetition.