Regarding Points

Does using Microsoft reward system halal?it's like they have a search engine as Microsoft bing (or the name slightly vary)so basically we have to do certain task to earn points and they will give us gift cards.those gift cards can be used in many ways I believe.But can I use them to get a game named Minecraft?(This is not a real life currency,they are like gift cards only possible to use on their products).there could be task where they may tell us to see a ad of bad stuff(tho it is said it's restricted and varies by age).It's basically using that search engine instead of google I believe and they reward you by doing certain task.I will try my be best to avoid the bad stuffs if they really come.So is it permissible?