I rarely spend money on software and honestly haven’t really played a computer game since Duke Nukem 3d was new. That said, I recently purchased Universe Sandbox2 and I’m loving it! It’s less of a game and more of a space physics simulator. My nephew and I have been enjoying playing with mass and gravity of different stellar bodies, exploding stars, and crashing planets into each other. It was around $25 and is definitely worth it. Learn more and get it here.