1) Чё - same as Что, but very colloquial (used when talking to a professor at school can be regarded as rude)

2) -то - усилительная частица. used for emphasis. At intermediate or advanced level of Russian, one understands how to use it. Дык -very colloquial for "так" (просторечие)

3) меня звать - просторечие (old-fashioned, as the previous poster said) normal way is always "меня зовут". меня зваль - doesn't exist.

4) Эт - просторечие... In fluent speech "о" may disappear. Пример: Эт как? (but the correct spelling is always Это как). In this computer game the spelling is alternative to make it sound very colloquial and somewhere is incorrect.

5) Сечешь? - просторечие. very colloquial. Like in English: you follow? you feel me? (meaning, Do you understand?)

by просторечие - i mean very colloquial use, or used in very casual speech, or sometimes characteristic of old-fashioned language...