What are the max amount of items that can be placed in Mario Maker?
There is a combined maximum of 2000 for the following items:
- Brick Block/Rotating Block
- ? Block
- Solid Block
- Ground Tile
- Coin
- Spike Trap/Jellectro/small Urchins
- Jump Block/Music Block
- Donut Block
- Cloud Block
- Hidden ? Block
- Tracks
There is a combined maximum of 200 for the following items, however, the size can be adjusted without problem:
- Pipe
- Semi-Solid Platform
- Bridges
- Vine
- Mushroom Platform
There is a combined maximum of 100 for the following items:
- Super Mushroom
- Mystery Mushroom/Raccoon Leaf/Cape Feather/Propeller Mushroom
- Fire Flower
- Super Star
- 1-Up Mushroom
There is a combined maximum of 100 for the following items:
- Trampoline
- Goomba
- Koopa Troopa
- Piranha Plant/Fire Piranha Plants/Jumping Piranha Plant
- Lakitu/Lakitu's Cloud (only Lakitu counts as 2 against the limit)
- Spiny/Spiny Helmet
- Platform/Loose Platform
- Bill Blaster/Red Homing Bill Blaster
- Blooper/Blooper Nannies
- Cheep Cheep
- Hammer Bro/Sledge Bro
- Buzzy Beetle/Buzzy Beetle helmet/Parabeetle
- Thwomp
- Lava Bubble/Podoboo
- Skull Raft/Bone Lift
- Fire Bar
- Rocky Wrench/Monty Mole
- Bob-Omb
- POW Block
- Rocket Engine
- Cannon
- Spike Top
- Boo/Circling Boo Buddies/Stretch
- Dry Bones/Fishbones
- Magikoopa
- P-Switch
- Muncher
- Wiggler
- Yoshi/Goomba's Shoe
- Koopa Clown Car
- Grinder
- Chain Chomp
- One-way Wall
Additionally, there is a maximum of:
- 100 Arrows
- 4 sets of Doors (8 doors in total)
- 3 Bowsers/Bowser Jr. in total
Items or enemies that have been put into blocks don't count against any limit.
Items or Enemies that have been put into pipes do count against their respective limits.
These limits are per level, and the limits count seperately for the level and sub-level.
Finally, A maximum of 10 pipes can be turned into a set of warp pipes, meaning there can be up to 10 connections between the regular level and the sublevel.
Source: Pushing the Object Limit in Super Mario Maker! video by GameXplain, groups manually verified by me.