Yes, you can use programs such as Ubuntu Software Center to remove your GOG Games. To do this, you will need to search for "gog" within the aplication. GOG Games are categorised as "unknown" and won't appear on the main list.
We will do our best to respond as quickly as possible. On weekdays, we normally reply within 24 hours, but during weekends we can only respond that quickly to high-priority, time-sensitive cases. All other cases will be looked into first thing next week.