In a word : yes. Blowback is a common issue when playing paintball. It is the excess gas vented from the marker through various ports (feed tube, barrel, etc.) and can make your marker a little less accurate with each shot unless you address the issue when you're lining up your shot.

Closed bolt markers have much less blowback because of their design, which allows less air in the form of blowback gas to escape. Blowback is essentially the leading origin of kick your marker may have or if you have a closed bolt marker, lack of kick.

If you use an open bolt marker, your paintball gun will most likely kick or rather jerk from your grip a little with each shot you fire. If you're using an open bolt marker, planning ahead when you aim at an opponent or target will result in a more hits with fewer paintballs used. If you have a closed bolt marker, your goal will be to learn to steady your arm with each shot fired as blowback won't be a big problem for you.

Also, when you're lining up a shot with your marker, be sure and take into consideration other elements such as the wind direction and speed, this will alternately work with you or against you depending on your position. If you are shooting into the wind, allow for that to slow your paintball a bit and realize it will slow down the velocity and you will need to a be little closer. If the wind is at your back, you can line up your shot and know that nothing is slowing your paintball down on that shot!

Accuracy is easy to attain in paintball if you practice with your marker on a regular basis and always take into consideration the outside conditions around each shot you make.