For some reason is registering the click on the left side of the button, the animation should change when you hover the mouse over it, you can use a controller or keyboard and mouse, or keyboard only too. I'll look into that detail. Or you can just hit enter when the button is jumping and it will start the game anyway.
Viewing post in Homotypic Cell Fusion jam comments
Oh ok got it! One thing as soon as you click you can't use the keyboard. So basically to press it with the keyboard you need to not interact with the game window and the mouse at all.
Glad we figured it cause the idea is great and the game is really fun. I like that every color mixing affects the output. Damn I ended up with a red thing consuming all my oxygen :D .
Really cool idea super well executed beside the start button.
Thank you very much, as soon as the game enters, is auto-selected the start button, and you can navigate through the options with WASD or controller arrows, but if you click in an area other than the buttons it deselect themselves, but still can click on the button, it changes the animation when you hover the mouse.