Hey!

I will cite a few examples:

There are a lot of cool stuff over there.

This one should read: "There is a lot of cool stuff over there."

Just in case the player wishes to undo his last step, he/she can do that by clicking on the icon below 'points'.

This one would be a better sentence: "Just in case the player wishes to undo their last step, they can do that by clicking on the icon below 'points'." In general, you can use "they/their/theirs" in cases where there's no information in regard to an individual's gender.

I hope you will find this comment useful.