Have different types of food

[osso73]

Establish different types of food, each type has a different behaviour. Some examples:

• food will grow snake by 1 (that's the default)
• food will grow snake by 2 (or 3)
• food will increase / decrease speed
• etc.

Different types may have different probabilities, i.e. the default should be coming most of the time, the others just occasionally.

[osso73]

Added 3 types of food, with different behaviour:

• fruit: add one snake part, and 2 points to the score. This is the healthy food!
• fast-food: increase the speed of the snake by 1.5 for a while, adds 2 snake parts, and one point of score.
• sweet: adds 3 parts of the snake, one point of score.

Given the points cumulate faster, I've increased the points required to move to the next level. This increases also the difficulty, since now your snake can become longer, especially if eating sweets!

Fruit is what you get most often.