I noticed the rules say to do a windows port so you can play everything submitted, but would I be able to do a playable in browser version?

Yes, you will be able to do that, as long as you can play it on windows.

Actually, I was about to publish my submission that is a web build (don't worry, my game totally sucks and I will  give it a bad score so I don't win my own Jam).

Alr, thank you :)