What does this idiom mean: to be into something?

[Ivrine]

English Error, Elementary Level

ESL/EFL Test #7 "English Prepositions", question 2

Are you up to the game of cricket or doesn't it interest you in the slightest?

(a) up to
(b) of
(c) in the slightest

English Error, Elementary Level

ESL/EFL Test #7 "English Prepositions", answer 2

Are you into the game of cricket or doesn't it interest you in the slightest?

Correct entry: into
The error was: (a) up to
_________________________

is in the slightest the correct answer for this questions?

Ivrine

[Lost_Soul]

[Conchita]

To be into something is to be interested in it or to like it very much: Are you into (the game of) cricket?

Now the question 'Are you up for a game of cricket' would refer to one particular match, not to cricket in general.