The Original Simple Rockets was a 2d rocket building game which proved to be an excellend substitute for Kerbal Space Program on mobile devices. Now Simple Rockets 2 is full 3D and is launching on PC, and while some people will dismiss it as a Kerbal clone, it's different enough to be a viable alternative to my favourite game. You can buy it through this link if you want to share a portion of the purchase price with me: https://www.humblebundle.com/store/simplerockets-2?partner=szyzyg