Are normal minecraft blocks features enought for you?
If not, discover 6 (soon 7) features that changes how will your player see blocks !

Blocks that gets a variant:

1. Sticky Slime blocks:

These blocks are variants of slime blocks that can be crafted using a slime block and an ender pearl.
When a player walks under this block, he cannot fall down !
When a player walks on this block, he cannot jump !
Please note that this feature is not supported by PocketMine-MP by the PMMP team.

Usability: Jumps, traps, and many other things !

2. Vacuum Hoppers:

These blocks are varients of hoppers ported from Open Blocks are hoppers that attract blocks from a 3 blocks distance.
They can be crafted using a hopper, an ender pearl, and an obsidian in a crafting table !
Please note that this feature is not supported by PocketMine-MP by the PMMP team.

Usability: Farms, Redstone systems, and many other things.

Features that can be applied to any block:

3. Fallable blocks:

Uppon walking on this blocks, it falls as sand, gravel or any other blocks !
To create them, it's a bit difficulter that before:
First of, craft an hammer using 3 materials (that could be wood planks, cobblestone, iron, gold, or diamond) along with 2 sticks).
Then hit any block to make it fallable.

Usability: Jumps, traps, world generation, and many other things.

4. Sound blocks:

These blocks plays a predefined sound when a player walks on it.
Drop a noteblock on it to make transform it as a Sound Block.
Hit it to change it's sound (you'll receive a popup with the choosen sound).

Usability: Role play, jumps, traps... Pretty meach everywhere.

5. Trap blocks (in dev):

These blocks will disappear when a player walks on it, then reappear 2 seconds later.
Craft a trapper using a stone pressure plate and a redstone then drop the trapper to set the blocks under it as a trap block. Please note that this feature is not supported by PocketMine-MP by the PMMP team.

Usability: Jumps, traps, and many other things !

6. Redstone Powering blocks (when redstone will be implemented):

These blocks emits a redstone signal when a player walks on it.
It's better than pressure plates because no sound is emited, it could be any blocks, and the player has no way to see it before getting on it.
Craft it by droping a redstone block on the ground and this block will become a redstone powering block.

Usability: Traps, redstone contraptions, ... Pretty much everywhere !

Other blocks:

7. Graves:

This block is also a port from Open Blocks and are made so when you die, all your inventory will be stored in a grave. You can get it back by breaking it.
A grave is composed of a cobblestone block and a sign with the name of the player, and how did he die.