The original link for the trial version can be found in the series wiki here: http://monstergirlquest.wikia.com/wiki/Monster_Girl_Quest:_Paradox

However, the English translation does not have a working link other than the mega link found here:
https://dargothtranslations.wordpress.com

I know you don't really need the English patch, I just put it there in case you were gonna ask for it.