It is understandable but requires an effort. A person familiar with the topic should understand. You did very well with the 44 phonemes of English. Most Russian speakers have trouble with /w/, /v/, /ð/, /θ/, and the vowels, but you have reasonably good versions of all the sounds. The major problem is the unnatural stress pattern, so almost every word sounds odd. A motivated listener will mentally convert each word to the standard pronunciation. This is fatiguing and hard to sustain during a 20-minute presentation. A conversation is less fatiguing because the speaker usually talks for a short time before giving the listener a turn to talk. For improvement, work on word stress, sentence stress, and intonation. I recommend Rachel's English on youtube. She is qualified and has short interesting videos.

Hi Petr, I have to be honest..it's quite difficult to understand anything you say, sorry. Pronunciation in English is quite important and the problems arise especially with vowels and words of common origin ,French/Latin. But don't worry, there is a solution..practice, practice, practice...that's it! :)