1500 M is the fourth subchapter of Chapter 7: The Summit B-Side in Celeste. The subchapter resembles Chapter 3 and uses that chapter's mechanics in new challenges. In the final room, after reaching the purple orb at the end, the player will be taken to the next subchapter.
Gameplay[]
Much like its A-Side counterpart, this subchapter will be focused on getting good dash timings on the right cycles to narrowly avoid moving sludges all over. A recommended strategy for a lot of this subchapter is leaving and re-entering rooms to consistently get the first cycle of the room and have much more consistency on the required timings.
Strategies[]
Room 1
The first spring you have to reach in this room is below a moving sludge going left and right isolated above dust bunnies all over. Jump off the ledge when the moving sludge is at either side and dash diagonally up-right which should let you land comfortably on the spring. After bouncing up, move right a bit until dashing straight right through the gap in the dust bunnies, then fall a bit more and dash straight right again into the wall and grab it. When the moving sludge above is at the bottom, wait and jump up onto the spring as soon as it starts going up, then move right until eventually doing an up-right dash followed by a straight up-dash to then grab the wall to the left. Jump to the right and land on the spring, then move right in the air after bouncing to then dash up-right and straight up to grab the next wall to the left. Watch the moving sludge to the right until it's at the bottom, then jump to the right when it's about to move up and land on the spring, then keep moving right and dash straight right and up-right through the dust bunnies and making it past the last moving sludge to reach the end.
Room 2
Watch the closest moving sludge to ensure your timing is right. Jump up into the spring when the moving sludge is leaving either edge, though it's easier when the moving sludge is at the bottom going up. In this scenario, dash straight right once, then again shortly after. This will land you at a checkpoint of the room at the midpoint. Watch the next set of moving sludges, jumping to the right and quickly dashing up-right when the closest one is at the top to reach a dash crystal. From here, fall a bit before dashing diagonally up-right once, then stalling a bit more, then do it again to reach another dash crystal. Fall a bit further before being able to dash up-right and quickly straight right to make it to the end.
Room 3
This will be a room where cycles are crucial to know and stalling in the air is very important for corrections. Jump off the ledge to the right and dash straight right, then straight up to the right of the spring, then fall to underneath the spring and grab the wall. Climb up to just below the spring and watch the set of two moving sludges to the right. Climb up into the spring when both moving sludges reach the edge to safely be bounced to the next section of the room. Depending on your cycle, many situations could arise from here, but generally your next actions should be aiming for the spring on the left to get a key token, then aim to land on the moving platform with a spring, stalling with a straight up dash if needed. Note that dashing straight up into the ceiling above can be helpful for manipulating your timing as opposed to in the open area to the left and right. For the key token below, stall for a bit until you see an opportunity where the moving platform and moving sludge are both at opposing sides, at which point you should fall into the key token and dash straight up once or twice to escape, then landing back on the spring. Bounce on the spring on the left side then dash straight up and grab the wall, waiting for the circling sludge to move to the lower half of its path to jump to the left for another key token, then hit the spring to the lower left again to reach the moving platform again. Watch the moving sludge to the upper right for when it's away from the wall to dash straight up and climb up above its path, then wait for it to move away from the right to jump into the key token and land on the spring below with a dash in whatever direction is needed. After bouncing on the moving spring and going right, dash straight right into the last key token, then jump to the left and dash straight up and you can reach the end corridor.
Room 4
This room is a single vertical corridor with moving sludges on diagonal paths and springs all over. The timings can seem overwhelmingly inconsistent at first, but there is always a guaranteed way to do it. Jump to the right when the first moving sludge goes to the top, then dash diagonally up-left into the spring as soon as it starts going down. Dash up-right two times into the next spring, then up-left two times to hit another spring. Let the moving sludge above pass to the right before doing two up-left dashes into yet another spring. Again, let the moving sludge above pass and go to the left before dashing up-left two times to bounce off another spring. Quickly dash up-right, then shortly after dash up-right again into the spring to the right to allow for the moving sludge to move behind you and allow you to be bounced left. Dash straight up, then the moving sludge to the left will move out of the way and allow you to dash up-left into the spring and be bounced back to the center of the room, just below the purple orb. Dash straight up twice to reach the purple orb and be taken to the next subchapter.