パックマンが、ある条件を満たすと追ってくるモンスターを逆襲して食べることができる。

、。

When Pac-Man meets a certain condition, he can turn the tables on the monsters chasing him and eat them.

Literal

Pac-Man [subject-が], certain condition [object-を] satisfy [conditional-と] chase-come monster [object-を] counter-attack-[and-して] eat thing [subject-が] can-do.

Video game mechanics explanation. 追ってくる is 追う ('to chase') + ~てくる ('action coming toward speaker') — 'chasing (towards us/Pac-Man).' Relative clause modifying モンスター. 逆襲する ('to counterattack, turn the tables') is a compound. ~ことができる is the formal potential construction ('is able to X'). Classic gaming documentation style.