NSMB Any% Notes

Flag Pole
--Landing above the flag is slower
--Landing facing left is faster

Blue Shell
--Shell is required for the World 1 warp
--You have a 1 in 6 chance of getting a shell in 1-2 (saves 12 seconds)
--First mushroom house has a backup shell
--Shell spinning speed is approximately 8% slower than running speed
--Unmorphing during jumps is faster because it's considered to be "running speed"
--Swimming speed is faster with shell

Momentum
--Landing on the exact corner of a ledge will make you lose all momentum, this is called a Pixel Stop
--Pixel stops can also occur on platforms that move up and down if you land on them at the right time, shell is not affected by this while spinning
--Star increases movement speed only while on the ground
--Running up or down a slope is slower
--Sliding down a small slope is faster than jumping past it
--Crouching at the end of a platform makes you fall faster and saves a little bit of time

World 1-Tower 1
--There are three cycles you can make:  Normal, Fast, and TAS cycle
--Normal cycle waits three cycles, is the safest
--Fast cycle waits two cycles, requires getting past the third crusher on second cycle (saves 7 seconds)
--TAS cycle waits one cycle, requires multiple frame perfect jumps (saves 14 seconds)

World 8-Tower 2
--There is an intentional death at the checkpoint which requires Fire Mario to do two damage boosts
--This is faster than waiting for the snake block to make it to the checkpoint by a few seconds

Difficult Levels Without Shell
5-2 (Narrow pathways, lots of enemies)
8-1 (BIRDS)
8-3 (water level)
8-4 (SPIDERS)

Difficult levels in general
8-Tower 1 (Cycle based vertical level, difficult to do well)
8-5 (Tight jumps in a speedrun, slight mistakes usually lead to a death)
8-6 (Vertical level with rising lava)
8-Castle 2 (Final boss has a precise quick kill, level is long with a single check point in the final hallway)