Where is Hyperspace Invaders I?

[HAUSER]

Also there is a not pixelated edition?

[Ein Ra]

check the dev's web

[Caligo Clarus]

Here: http://hii.entity.be/

[EntityMedialab]

yes, older versions (HI0, HII and HIII) can be found at the Entity Medialab page.
http://medialab.entity.be
But honestly I don't really recommend it unless you're up for a nostalgic trip.
You should know that Hyperspace Invaders has always been the same game, just with added development time, bugfixes and multiple overhauls / game engine updates to it.
HIII:PE is the most stable one at the moment. HIII:DX will push the bar a little bit higher, so stay tuned :)