I really miss working on my game hobby projects but realistically don't have the time right now for hours each day what with work and other hobbies. My past projects were all big, ambitious games like an RTS, a driving game/simulator, etc... a whole day's work as I used to do and maybe you refactored your sprite class or improved your level editor.

If you wanted just to be able to throw games together really fast and spend the minimum time on anything that isn't gameplay, what would you do? I'm leaving this open as regards game style, technology/languages, platform... if you wanted every minute to count and you wanted to see a playable game almost from the very start where every hour's work you can see a tangible output...

(I'm a professional developer with a background in games, graphics and business coding so I like to think I'm fairly competent)

I'd grab an engine or game-making program that had already been shown to be capable of creating the kind of game I want, and use that.

I don't think there's an all-purpose answer because the abstract answer is always "get someone else to do the work for you" and the type of work you need to be done depends on the type of game you want to make.

It's art that scuppers me.

Simply find an existing engine or framework and use it, finding the graphics and sound is the hard bit...

For sound, there is a decent selection of royalty free sound out there. It can be kind of tedious to go look for it, and much tweaking still has to be done, but it's there.

Art...not as much, it's not too hard to find free art, which is probably fine for placeholder, a little harder to find royalty free art. A good compromise, if one is already using an engine with an asset store, might be to visit that and buy whatever one needs.

I think it's important to not get too hung up on art or sounds, depending on the game of course, but a game should be fun and playable with sub par art that could be replaced as needed. (Post Kickstarter, or whatever)

I'd grab an engine or game-making program that had already been shown to be capable of creating the kind of game I want, and use that.

IMO engines are great for bigger projects but for something small the overhead of setting it up and learning how it works is non-trivial? That said I've not used the more modern engines, maybe they do let you have something right out of the box?

Where are we at in 2017 regarding game-makers... I recall 10 years ago one of the better 4E4 entrants used GameMaker or something like that. Are they still popular, is there a definitive tool people use or just loads of competing products?

Unreal, cyringine, unity... those might give the fastests results. The first 3 times: I tried, I failed, and I overreached. I've a bit of experience and this month I managed to make a single thing that's not crap. I think it has to do with practice, and it's not something you could write of, there's a sense of things that needs to be built up (It's not as easy as shamlessfully ignore the ugly and bad).