​Metroid Prime 2: Echoes (GC, 2004)

• Mostly linear structure (completely linear with various temporary points of no return up until after the first mini-boss (about 1h30m in), nearly linear path up until you get the bombs back and you can only access the first temple in the dark world after that - if you try to go to torvus via the great temple you're met with a purple crystal gate and if you sidetrack to other parts of the dark world or explore more of the light world you run into other gates, the three main areas and the final one are reached in a set order and you get your abilities in a set order as well, can do part of the underwater sub area of torvus in either order, keys can sometimes be found in any order and various optional upgrades can be gotten in any order once you have the right ability, might be possible to go into the super toxic dark world wastes area for an upgrade early (without the light suit) but it's very hard, )

• Frequent save points which also heal you (single save slot per game but can copy the file in the system menu), Some ammo stations

• Adds a teleportation ability via the light suit though you get it very late. Can teleport to restored temples (one per area in these areas - Agon, Torvus, Sanctuary, Great Temple). Some shortcuts

• Some new tools/weapons (dark beam - opens portals to dark world+opens dark doors+"freezes" groups enemies if charged (no ice beam here)+activate certain crystal gates/switches, light beam - opens portals to light world+opens light doors+more damage vs dark world enemies+multiple homing beams when charged+energize beacons to damage dark world enemies+activate certain crystal gates/switches, annihilator beam=light+dark energy (opens portals) and auto-homing+stun enemies with charged beam and draw enemies into powered up beacon lights+open alternate echo gates via note puzzles)

• Compass added to the map screen (see Prime 1 otherwise), Optional hint system (text tutorial messages here and there (doesn't pause gameplay but is a bit too obvious at times), sub objective markers on the map - these show the goal room to get the next ability but not the route to it), Color coded scannable objects (makes it easy to tell what is important for progression to scan), Map stations that reveal most of the current area when found

• The safe zones mechanic in the dark world create a good sense of vulnerability - shoot beacons to create temporary ones in preplaced spots)

• Some scripted non-cutscene scenes which add to immersion (seeing the pirates interacting with objects and metroids carrying newly consumed ones later on, fight between pirates and dark samus, etc.)

• Some neutral creatures that help you in a way (lightbringers - moving safe zone beacons in the dark world, herd of small drones which can be killed for item drops in the fortress area, flying maintenance bots in the fortress, watchdrones move out of the way when activating beacons near them)

• Various new enemies are added to previous areas when you backtrack through them (generally not ones you've never seen before though)

• Can stand on some frozen/encapsulated enemies (not sure if it's useful though)

• Some sequence breaking opportunities but no major ones without glitches (bypass getting the keys to the Hive Temple with bomb jump+screw attack, enter torvus before dark suit with slope jump/ghetto jump, more minor skips with scan dashing/side hopping while locked on+slope jumping+standing on unintended surfaces in the environment)

• Can perform a roll jump similar to Metroid 2 or DKC (while holding R in ball form, unmorph+jump at the right time as you fall off a ledge+hold L right after unmorphing to keep your speed) however it's tricky to pull off consistently. Can also perform a double jump after a bomb jump by doing it with your back against a wall, going forward a bit then pressing back while doing it - tricky

• Environmental gameplay effects (various mechanisms being activated or deactivated, some manipulation of larger objects via switches or breaking walls, dark samus taking out a bridge at one point, sand mound drainage in one room, water draining (gathering hall)) - somewhat fewer large scale ones than in the prequel

• Some good puzzles (seeker launcher circular tiles sliding puzzle, some platforming/disappearing block puzzles in ball form, ) and some decent ones (staircase blocks in pirate base, sacred bridge gate, some spatial reasoning ones, etc)

• Three endings ("barebones"=less than 75% completion, "extended"=75% or more, "full"=100% completion)

• Slow regeneration while in safe zones in the dark world

• Some pits however you lose only a bit of health from falling into one and get respawned on the last platform you stood on

• Unlockable hard mode but it's kind of boring (enemies have twice the usual health and their attacks do 1.5x the normal amount of damage)

• Silent protagonist unlike in Fusion

• Enemies don't keep dropping items which you already have a full stock of here however some enemies don't drop light and dark beam ammo at all

• Can't do a charge/cluster bomb attack here (charge the beam then go into ball form to release a cluster of bombs), No plasma beam/flamethrower or wavebuster and no phazon suit or beam, Still can't grab onto nor climb ledges (Fusion), Still no shinespark or speed booster for faster movement while not in ball form
  Some notable cons:

• Can't lock onto enemies while in ball form (boost ball is used as an attack against some enemies here)

• Unskippable cutscenes+staff roll besides some repeating ones

• Still no right stick aiming, Still no full control config

• Can't add your own notes/markers to the map - several ability gates early on and unlike SM a room with an item in it isn't marked by a dot plus some gates aren't shown on the map

• Can't be grabbing most of the 9 sky temple keys over the course of the game due to gear requirements

• Activated world portals don't stay active - have to rescan them each time, Opened dark beam and light beam doors don't stay opened or switched to blue doors - ammo-based beams+it's annoying to switch beams all the time+the stacked annihilator beam doesn't work on them

• Some gates placed right after newly opened gates

• Backtracking to restore temples and back to the temple grounds after dark suit+some other lengthy ones

• Harder to hit some enemies with charge shots and various enemies and bosses have frequent invincibility periods

• Constant beeping sfx while near death
  

Playthrough - Video Review - Mini Review

Influenced by: Zelda series (structure, parallel worlds), possibly Tron or Blade Runner (fortress), see Prime 1

Influenced: Possibly Geist, Bioshock