Hi babaliaris,
Glad to see you're trying out pygame. Just a suggestion, but even though you can see the code in the video, it's still a good idea to paste or provide a link to it in your email.
This is something I've encountered before. It doesn't really have anything to do with the number of images you're blitting (only a very small percentage of those are even being written to the screen, see?) It's a limitation due to the coordinates being 16-bit integers. When those go past 32,767 (for signed, which allow negative and positive values), it starts back at -32,767 and continues until we hit positive values you would see on the screen. Since those are starting at an odd number, you end up with the 'offset' images you see in your output.
Python 3 supports much larger numbers. iirc, the default for an integer is as much as a full Long -- so it should match the maximum allowable value for your environment. Pygame is still using 16-bit integers for blitting, though. One thing to remember is that all of those very large values are wayyyy outside the coordinates you are actually using in your display 600x600 window. Anyway, you will want to do something like storing the absolute location of an object and also the location (rect) of a 'camera'. Then you can do a calculation to find where you should display the object (if at all) by finding out where it is in relation to your camera rect. I usually keep track of 2 rectangles per object; a hrect (as in "hit" rect) for absolute value / collisions, and a rect that is its location in relation to the camera (and named 'rect' so it will be used by the sprite group's draw method). Something like..
class Thing(pygame.sprite.Sprite):
def __init__(self, x, y):
self.x, self.y = x, y
self.image = pygame.image.load("dude.png")
self.rect = self.image.get_rect()
self.hrect = self.rect.copy()
self.hrect.topleft = self.x, self.y
...
def update(self, camera):
# logic to update self.x and self.y goes here
self.hrect.topleft = self.x, self.y
self.rect.topleft = self.x - camera.x, self.y - camera.y
Hope that helps.