That's not really a resolution issue. While in the game press Esc on the keyboard, click the Edit Mode button, put a mark in the box next to 3D World Editing. Now you can resize the 3D viewing area by placing your cursor at the corner or edge of the viewing area box, then clicking and dragging your cursor. When you're done click on Save and Exit.
Awesome to hear that the issue has been resolved, I'll give this thread a gentle lock now, but if you have more technical issues in the future, please do create another thread in these technical sections and we would love to help you out again.