The enemies in Echo copy any action that you perform until they're highly dangerous walking death machines.
Level design and smart enemy placement turn Echo's stealth gameplay into something really special. I take a look in this critical video.
Echo is a stealth puzzle game where enemies learn new abilities based on what the player does. Echo raises and lowers its difficulty by forcing the player to carry out different actions depending on level design and enemy placement. Ramping up the complexity of scenarios, either by adding more enemies or objectives, helps the designers modulate how hard or easy the game becomes.
Echo tells the story on En, a young girl on the run from the dangerous cult who raised her while on a quest to revive her mentor. To accomplish this she must brave the Palace, a massive planet-wide structure of traps. The Palace is populated by creatures En calls 'echoes,' strange copies of her that are shaped out of a black muck at the start of the game.
Whatever En does while the Palace's lights are on, from eating fruit to opening doors, the echoes learn how to do as well once. There is a period of darkness between light cycles in which En can perform actions without the echoes copying her. It's a fun mechanic that the designers play with in numerous ways.
One of the first encounters with the echoes involves two rooms filled with water. In the first room, the echoes are on the other side of water while the player crosses a pathway.
The echoes can't reach the player because they don't know how to cross water. In the second room, the player is forced to cross water on their way across. When they return through the room, the echoes have learned to walk in the water. Guiding the player to use certain hazards or perform key actions is one of the main techniques the game uses to increase difficulty.
By forcing the player to cross water or use elevators, the game can create rooms where the echoes will always have certain abilities. This removes any potential crutches the player might have relied on, such as waiting until it's dark to use an elevator.
Echo's level design also tempts the player into performing certain actions. Avoiding the echoes by crossing water or leaping over a small wall can keep you out of their path temporarily but will cause trouble later on.
There's another twist though: if you stop performing actions the echoes have learned, they will eventually forget how to do those things after the light cycle resets their memory. Actions become a cost/benefit analysis in which the player must decide if they want to use multiple actions to make things easier now or if they want to take a risk at besting the echoes with minimal actions so they can save them for later.
In a late game corridor, for instance, a stretch of stairs leads right to where you need to go, but there are multiple echoes in your path. You can avoid them by opening a door and moving to a side hallway. The player has to choose if they want to risk the enemy-filled hallway or avoid the echoes but teach them how to open doors.
They can undo this action by waiting through the light cycles until the echoes forget how to use doors, but remaining still is made difficult by patrolling enemies.
Echo adjusts certain variables to encourage this kind of decision making. The simplest way the game does this is by increasing how many things the player must deal with at any given time.
You can have a room with three echoes or a room more than a dozen. Some doors will only open if the player collects a certain amount of orbs from around the room. This often means increasing the size of the room as well. The larger space and high number of orbs requires the player to spend more time avoiding echoes and means they have to weigh more actions and their consequences.
Funelling the player towards enemies is another tactic the game uses to adjust its difficulty. Small walkways encourage players to sprint or use their gun, useful abilities that the player won't want the echoes to learn.
Orbs can be blocked by enemies that are most easily avoided by performing certain actions like climbing or walking through water. In some instances, there may be less enemies, but there are also fewer options for dealing with them without teaching them new abilities.
By adjusting the size of rooms and changing the number of enemies, Echo creates scenarios of varying complexity. Limiting the potential actions a player can take or forcing them to use certain actions to proceed lets the designers make more difficult encounters.
In the best cases, players have to carefully decide what actions they will use and whether or not they risk creating deadlier echoes. Little tweaks, like narrowing walkways or adding one extra puddle of water, have drastic repercussions that test the player and keep the game exciting.