It's easy for a game to be defined by a gameplay mechanic that eclipses everything else about it. Shadow of Mordor became all about the Nemesis system, even though the mechanic isn't introduced until halfway through the title. Echo is a stealth/puzzle game with many standard core mechanics and one big, exciting, innovative core mechanic that will determine whether you like the game. It's fair to say that if you aren't excited about the concept of echoes, then you're going to have a tough time enjoying Echo. It isn't necessarily a flaw, as developer Ultra Ultra executes well on the concept.

Echo is set in the far future. A woman named En wakes up after a lengthy cryosleep, and she's alone on a giant ship. En has traveled far across the universe with a sarcastic AI named London. Together, the two attempt to locate The Palace, which is known for advanced technology, and En hopes to use this technology to undo a terrible mistake in her past. Unfortunately for her, The Palace is not a friendly place, and she has to put her life on the line to access its technology.

Echo's story is rather bare-bones. You'll get a lengthy exposition dump in the beginning, and more bits of information trickle out as the game progresses. The setting and characters are interesting, but The Palace isn't the place for them to shine. I wanted to see more of the unusual outside world instead. Echo paints a futuristic world setting, where technology has advanced so far that it sounds indistinguishable from magic. I'd love to see another game in a universe like this, but perhaps not one with the same setting.

It's important for a game to get off to a strong start, and unfortunately, Echo doesn't. The first hour or so consists of tedious walking through identical environments while the game very slowly attempts to build its characters and world setting. While this isn't uncommon for games, Echo has one of the most energy-sapping starts I've ever encountered. Every time I thought I was about to start playing the game instead of wandering around, it kept going. It's a real shame, but it would be very easy to write off the game before you actually get to what it offers.

That would be a shame because what Echo is pretty distinctive. Itcan be described as a blend of the stealth and puzzle genres, which makes sense since developer Ultra Ultra consists of some former Hitman staffers. Don't mistake that for meaning Echo is a Hitman clone, though; it shares the same basic stealth-with-some-action mechanics as the franchise, but that's about it. You get some more esoteric abilities as the game progresses, but you'll spend most of your time sneaking around, ducking, hiding, performing stealth takedowns, and occasionally using your surprisingly powerful pistol. If you've played any modern stealth game, Echo is going to feel familiar.

Probably the most distinctive element of the game are the titular Echoes, which are echoes of another being. The Echoes are almost exact physical copies of En, but they're not exact mental copies of her. When they're introduced, they are little more than shambling zombies who are a threat to no one.  They wander around, and they can be a mild threat, but it's easy to escape them since they won't cross the water or look over ledges.  

The trick is that The Palace suffers from intermittent blackouts. When the lights are on, the game records everything En does, including actions like running, leaping over ledges, using weapons, and performing stealth takedowns. Regardless of the action you take, the game is watching it. Once the lights go out, you have a few minutes when the recording stops. When the lights come back on, the enemies suddenly evolve. All actions are fed into the Echoes' AI, and they have access to anything you've done until the next blackout. The only thing stopping them from becoming unstoppable is that the echo only lasts until the lights go out again.  The Echoes evolve with each cycle, so you'll have to stay on your toes since every strength is also a weakness.

It's a pretty cool concept that works surprisingly well. There are a lot of different ways to approach completing your objectives, but in doing so, you have to consider which tools you're giving to the enemy. If you go in with guns blazing, you may face some deadly gun-wielding enemies. If you're sneaky, they adapt to how you're being sneaky. Any upgrades or abilities you get make you stronger, but they also make the enemy stronger. Additionally, there are periods of downtime during blackouts during which you can go all-out, but you need to think carefully and be in position to exploit them.

The system isn't perfect, but the echo effect is extremely cool. In video games, it's incredibly easy to fall into habits, and this is doubly true in stealth games. Once you know which tactics work, it's so easy to keep using them over and over again. The echoing effect of your own movements turns that on its head; you can't keep playing the same way because the game won't allow it. Every tool you use is one you can give to your enemy. In turn, that means you need to understand the strengths and the weaknesses of any actions you take. Once you play long enough, you'll understand how the enemy AI can exploit what you do and where it fails to understand the full potential of the tools it's been given.

This is where the puzzle element of Echo comes into play. Most stealth games are less about true stealth and more about figuring out how to exploit the AI. Rarely are you worried about what the enemy sees but what the enemy's AI will do in a given situation. Echo takes that mechanic and makes it the core idea. The entire game is a puzzle about figuring out how to exploit the AI, which constantly changes to match how you exploit it. As with any AI, you'll eventually figure out its flaws and foibles. The genius of the game is that doing that feels intentional, not like you've noticed flaws in the system.  Certainly you have noticed a flaw, but it makes you feel clever.

Echo is surprisingly fun for what it is. It gets repetitive, the environments don't have enough variety to support the 8- to 10-hour running time, and the adaptive enemies start to lose their luster long before you reach the end of the plot. However, it's never bad, and once you get past the tedious opening, the game is strong more often than it's weak. I don't think the premise could've supported much more gameplay without more complex mechanics, environment or enemies, but for what it is, it lasts just long enough to be enjoyable but long too long to lose itself.  There are some reasons to replay the game, but it depends on how much fun you've had in exploiting the core mechanics.

Echo is a surprisingly nice-looking game. The character models and environments are detailed and well designed, and there's a lot to like. The biggest problem is that the PS4 has some trouble running the game. The loading times upon any death are uncomfortably long, and there are some serious frame rate drops. Weirdly, these seem localized to non-combat areas, so it may be a side effect of the game struggling to load the next area, but it's very noticeable when it hitches up and freezes. The voice acting is largely solid, which is important.

Echo is a fun and enjoyable game defined by a well-executed gimmick. Without the adapting Echoes, it would be a standard stealth shooter. With the Echoes, it becomes distinctive and interesting. The adapting AI is as much a proof of concept as a fun gameplay mechanic, but it works very well at being both. Echo shows that modern stealth games have a whole lot of room to grow and evolve. For fans of the genre, it's well worth playing, assuming you can get past the slow start and occasional technical hiccups.

Score: 8.0/10