Answer:
There would be no seasons.
Explanation:
The tilt of the Earth's axis is what causes seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere. If there was no tilt, the rays hitting the Earth would have minimal changes, meaning no seasons.