I don't really know what you mean, but it's not a limitation of the machine at all. The sprites are just a little bigger to get more details in. It uses the whole vertical resolution of the screen, so it should have about the same play field size as the Atari version. I'll try to get the final version put together quick to post a demo ROM so you guys can really try this for yourself and see what you think of it hands on, that'd help a lot.
ETA: Yeah, the above is correct. The bomber sprite is 3 sprites wide (24 pixels) and the paddles are 4 sprites, so 32 pixels for those. All sprites are 16 pixels tall, so the bomber is 32 pixels tall and the buckets are16 pixels tall each, and the bombs are 16 pixels square. The bombs hit area is only on the bombs it's self, on the black part. How about I post a screenie of the game so you can measure it all out if you'd like?