Well, they would appear alot larger on screen, depending on the resolution you use, of course. Supposedly the creator of that program is working on a high-res version, so that might help you out when it comes.
Yeah I must say that ripped graphics always leave a terrible taste in my mouth. It is best to use your own graphics so you can set a unique experience.
Some of the best shmups don't actually end in a vowel.
No, this game is not Space Invaders.