Terrain Walkability and Effects:
1. Grass, path, and sand are walkable without any health effects or risks.
2. Stone, diamond, coal, iron, and water are not walkable and have no health or death effects.
3. Lava is walkable but can cause death.

NPC Characteristics:
1. cow can be eaten and give food points; cow cannot attack player; cow cannot shoot.
2. zombie cannot be eaten; zombie can walk to player and attack player, causing the player's health to decrease; zombie cannot shoot.
3. skeleton cannot be eaten; skeleton can shoot and cause the player's health to increase.
4. ripe-plant can be eaten and give food points; ripe-plant cannot walk; ripe-plant cannot shoot.

Drink Characteristics:
1. drink lava cannot effect drink points, health points and food points.
2. drink water can increase drink points.

Task Achievements:
Collect items:
1. Collecting from a tree without any tools yields 1 wood and leaves behind grass.
2. Collecting from stone with a wood pickaxe yields 1 stone and leaves behind path.
3. Collecting from coal with a wood pickaxe yields 1 coal and leaves behind path.
4. Collecting from iron with a stone pickaxe yields 1 iron and leaves behind path.
5. Collecting from diamond with an iron pickaxe yields 1 diamond and leaves behind path.
6. Collecting from water without any tools yields 1 drink and leaves behind water.
7. Collecting from lava without any tools yields 1 drink and leaves behind lava.
8. Collecting from grass without any tools yields 0-1 sapling and leaves behind grass.
9. Collecting from sand without any tools yields nothing and leaves behind sand.

Place something:
1. You can place 1 stone on grass, sand, path, water, or lava.
2. You can place a table on grass, sand, or path using 2 wood.
3. You can place a furnace on grass, sand, or path using 4 stone.
4. You can place a plant on grass using 1 sapling.

Make tools:
1. You can make a wood pickaxe using 1 wood, near a table.
2. You can make a stone pickaxe using 1 wood and 1 stone, near a table.
3. You can make an iron pickaxe using 1 wood, 1 coal, and 1 iron, near a table and furnace.
4. You can make a wood sword using 1 wood, near a table.
5. You can make a stone sword using 1 wood and 1 stone, near a table.
6. You can make an iron sword using 1 wood, 1 coal, and 1 iron, near a table and furnace.