Hi, try playing in a different resolution. One of the bugs I found late in the jam causes the play button on the preface to be off screen :/. After that you should have a 'play' button you can click. I've verified that this works on 1024x768 and 1920x1080, and typically anything close to that. It should look something like this:
I intend to come back and make some fixes for these kind of things, but it's been a busy year with a big update coming to Death Game+!
TIP: You can craft certain items by dropping them together on the 'grass patch' in your main cave.
Thanks for playing!