It is modern English, it is generally comprehensible, but it isn't easy for the modern speaker. The main reason is that Shakespeare is full of familiar words that have secondary meanings that are uncommon or unusual for us now. So we find it hard to parse because a word we tend to use as a verb might be a noun, for instance.

An example off the time of my head would be the word "fast", which we usually use to mean "quick", but Shakespeare uses to mean "held tight". Speaking of "quick", he would use that to mean "alive".

If you really think about each line you might be able to work it out without notes, but that doesn't make it very easy to read.