Hello,
thank you for playing and review, I'm sorry about the "too easy" difficulty that is absolutely not working as expected. I wanted to fix this for the next release, that will come along with a bunch of new stuff and some more polished works. I hope you enjoyed it through the other difficulty settings anyway; still hard, I must admit, but certified beatable ;)
I'm glad that you could notice references to Parodius, and yes, powerups, enemies patterns, even some level design are ripped off directly from Gradius games ; not very original, I know, but it helped me a lot to determine a scope on this project in terms of content.
Hopefully i'll upload a fixed and up to date version of the game by the end of the week, please let me know if you ever give it another try :)
Cheers !