This is an amazing game! The best part I found was the transition effect. I am assuming you did something like… screen -> blit current dimension surf1 -> blit other dimension surf2 -> fill with black and add a white circle surf1 -> blit surf2 with BLEND_RGB_MULT flag screen -> blit surf1 I may be overcomplicating things tho, but for now it seems like a reasonable approach hehe. Also, as the bird is replaced with worms in the exact position in the new dimension, it is not required to determine the collisions exactly, that’s a concept-based workaround to something that would typically involve determining the hitboxes that fall within the ‘circle’ to the new dimension, and then detecting the collisions accordingly. Overall, it is a really interesting game with a great visual effect for dimension-switching!