Other "eatable" kinds of tiles/objects

[thejoshwolfe]

First implemented by @Patashu in #24.

The idea is to pick apart the different mechanics of fruits and make different kinds of things like them. Here are the independent properties of fruits:

• Immobile: doesn't fall, can't be pushed.
• Can only be eaten/destroyed by the head of a snake, as opposed to any indirect pushing force.
• Makes a snake grow when eaten.
• You're required to eat/destroy all fruits to open the exit.

Some other combo ideas of the above are:

Dirt: Immobile, eaten by the head of a snake.

Foam: Immobile, can be destroyed by any indirect pushing force, but not gravity.

We can imagine more objects with other combos of the above:

Keys: mobile, can only be eaten by snake heads, (doesn't make you grow), required to open the exit.

Glass Blocks: mobile, destroyed by indirect force.

Bunch of Grapes: several fruits bound together like a block, mobile (falls, and can be moved by indirect force), each grape makes you grow when eaten, required to exit.

[XeroOl]

Other ideas:
Fruit that shrinks snake instead of growing. (Would be interesting in levels like my Fruit Maze level)
Fruits that are attached to blocks. (It would move in relation to the block)