Hey there, ZUMSTEIN.
If I were you I wouldn't choose the word heavy. Although it is used in informal conversations rergarding this topic, some subjects such as computer files and games are usually described using size words, not weight words which are more appropriate to describe physical objects or a specific person or situation.
>> Quite not fare but it is heavy game to run for sure. [INFORMAL]
- a heavy fine = uma multa pesada.
- a heavy rain = uma chuva forte.
- to be a heavy smoker = ser um fumante ativo; assíduo / fumar muito
- a heavy traffic = um tráfego intenso.
REFERENCE: Pearson Education. Longman Dictionary. 2004.