Always love The Incredible machine series. There is a Rube Goldberg app for IOS and Android, but it was disappointingly short. Nicely based on actual Goldberg cartoons, but not very many - I completed it on a single plane flight.
The last serious playing I did was back with Return to Castle Wolfenstein and the original Call of Duty. You know, back when instead of relying on the game company's servers, you ran your own. And they had scripting code so you could make mods to the games. I played with an online group where we were all fans of using the sniper rifles. In general online play we were often called cheaters because of our accuracy, so we made our own server and our own maps specially designed for a sniper v sniper gameplay - in cases where other weapons could be found, they actually did no damage. It was fun to find some disgruntled wannabe spawn with a machine gun and you could just stand there while they unloaded and nothing would happen to you. In CoD we had an option as mods to turn someone into a flaming cow. Literally, a cow on fire would be running around/ The worst possible thing would be to be killed by someone who was turned into the cow - they had about 30 seconds of life but they could still shoot you.
I've been on the Kerbal thing since it was first offered in beta, but I haven't played much lately. I also got heavily into World of Tanks, WWII era tank combat, but haven't played that for a while either.