Hehe only one problem, I don't know how hard is Polish to learn  :D

Polish is very difficult, even very often one sees Polish people making spelling and grammar mistakes.
When I did Russian in school, I remember that everything seemed very simple and logical to learn.
Only trouble I have with Russian is reading Cyrllic. It takes me long to convert every letter.
This is why I always admired people from Cyrllic countries, to be able to easily switch from Latin to Cyrillic.

Slovio is a mixture of all Slavic languages so all Slavs can understand it.

there is no doubt about that

I can understand it, but it's very weird. They use letter X very much. I have never seen it used like that in any Slavic language.