I've spent some time prototyping with Defold and found it a joy to work with. The write once run anywhere is great but the real power comes from live changes. Y

I've spent some time prototyping with Defold and found it a joy to work with. The write once run anywhere is great but the real power comes from live changes. You can edit code while the game is running and see live changes. Iterations taking a few seconds (even on target platform) is a huge win for game devs. I'd recommend checking it out as an alternative to Unity if you are making a 2D game.