2500 M is the sixth subchapter of Chapter 7: The Summit B-Side in Celeste. The subchapter resembles Chapter 5 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[]
A big part of the challenges in this subchapter is needing good knowledge of swap block momentum. Dashing into oncoming swap blocks to get large boosts the other direction or just letting go as they arrive to get a vertical boost will be important mechanics to be aware of in this subchapter.
Strategies[]
Room 1
Jump up to stand next to the spring on the ground and jump on it. While not staying too far to the left with your bounce, dash straight to the left and boost off the swap block to get launched far to the right over the layer of crystals, then do one more dash to make it to the disappearing platform. When the disappearing platform vanishes, dash straight left into the swap block below and use the momentum to boost to the right again, then dash straight up and climb to the ending ledge.
Room 2
This room will contain corridors very narrowly divided by tons of spikes and traversal is exclusively via red bubbles. Follow the first red bubble's path to the right, dashing straight up and straight right accordingly to reach the next red bubble. Aim this red bubble straight down, then dash right out of it to make it between the spikes above and below, then dash straight up into another red bubble. Take this red bubble down-right, then shortly after dash diagonally up-right twice to make it to another red bubble. This red bubble should be taken up-right almost to the point of colliding with the spikes on the ceiling, but just before hitting them you should dash straight right and hold left to hug the left wall as you descend. You can then dash right to another red bubble and follow its path to the right, dash straight up and left, and you'll be at the last red bubble. Take it straight up and shortly after dash straight right twice, then hold left to make sure you don't land on the last set of spikes.
Room 3
This room will have tricky swap block locations that make you need to predict where they will be and dash accordingly. Jump off the starting ledge and dash up-right to reach where the swap block to the right will be. Wall jump quickly to the left and back right off of another swap block. This will align you to easily dash straight right and grab a swap block. Climb up it as it rises back up, and just as it reaches the top, let go to give yourself a boost upward, then move right to get to the other side of the crystals. Fall straight down from the right side of the swap block to reach a spring, off of which you'll bounce to the right and be able to grab another swap block. Jump to the left and dash up-right, then grab the swap block where it arrives up above the crystals. Quickly climb as high as possible, then jump right to aim to grab the left side of the other nearby swap block. You can then jump over it and wall jump off its right side to make it to a lower area, then dash straight left into the dash crystal and you'll be blocked by the swap block when it goes down, allowing you to grab it. After this, you can proceed to jump to the right and dash up-right, then straight up and climb up the last swap block in the room, quickly going right to avoid being brought up into crystals above.
Room 4
This room is very tall and will have many sections to test your skills. First, you'll need to jump and dash left into the swap block, using the momentum to go far to the right and dash up-right into the purple orb. You'll be thrust between a retracting swap block and the right wall, so grab the right side of the swap block and jump over it to the left, then dash right to get a big boost left which allows you to dash up into the purple orb again. From where you arrive, jump into the red bubble and take it right, then dash down-right and up-right in quick succession to avoid crystals in the way and reach the purple orb. Grab the right wall for the next section, then jump left and dash up-left just into the dash crystal. Fall a bit, then dash straight left and straight up into the other dash crystal, then fall and dash straight left and straight up into the purple orb. Climb up the left wall or just dash straight up to get into the red bubble above. Take it straight right into the next red bubble, then take that one down-left into the next red bubble, then take that one straight right again to go directly to the purple orb. After being thrown up from the purple orb, dash straight up twice and make your way up to the last section. This contraption will require a different method of swap block momentum, and to access it you'll need to stand on the left edge and dash up-left, trying to then land on the swap block. Stand facing left, then when the swap block begins to retreat back right hit the dash button and then quickly jump left, and then you'll be flung fast to the left and crash into the left wall. Climb up from here and use your two dashes to reach the purple orb and and be taken to the next subchapter.