Hi! That's strange, we'll have a look at this and try to find what's happening. Were you able to play only once before the button got disabled? Does the button appear visually disabled (grayed out) too? Have you tried clicking with the mouse or did you use a gamepad?
We're really glad that your son loves the game!
Hey :) Same problem here. I downloaded a beta a long time ago, thought it was a problem due to the old version, so I got the latest one from here, "New Game" is still unavailable. Grayed out, so neither mouse or gamepad works.
(Je contribue en anglais puisque poursuivant la conversation, mais si je peux aider à trouver l'origine du problème, je précise tout de même que je suis français. ce sera peut-être plus pratique.)
I just found the issue, it's now fixed. I'm currently building a new version of the game and I'll upload it as soon as possible :)
This is what the screen looks like for us. The button is disabled and we can't click on it using a mouse. My son was able to play several times before we ran into this issue. He's also tried playing with XBox and PlayStation gamepads.