There are two different types of traffic that are classified by most ISP's.
One is your "Bandwidth"Traffic. They classify this as interent surfing among websites - gaming falls into this category. ISP limitations usually do not apply here.
The second is your "Data Traffic". They classify this as downloading physical data of any kind, and this is usually where the ISP gives you a limitation.
Most ISP's use these generalized rules, but you should check with your isp first to see if they do or not, and ask them if your acocunt useage % has increased after you have TG'd overnight.