Same. It takes a little effort to read but it's understandable and it does feel Croatian or thereabouts. On a somewhat funny note, Chrome decided to translate the page in Interslavic from Czech to Polish and did a passable job.
What I find fascinating about Slavic languages is that I can speak Polish in Slovakia*, get responses in Slovak and mostly understand each other. It has basically zero chance of success in the Czech Republic to the point where it's easier to find an English speaker. I speak neither Czech nor Slovak and I cannot really distinguish them but I had this experience multiple times. In written form, both are similarly understandable to me (I can get the gist and guess the rest).
* the caveat about szukanie czegoś do picia still applies though.