Funny you should ask! TL;DR please consider Out There Somewhere! Sales pitch below. :)
I just finished a stream of Out There Somewhere, a 2D platformer available on Steam. Standard price is $2.00 US, but it often goes on sale, and in a bundle with Camera Obscura, Polarity, and BEEP.
The game has three main categories, all under 15 minutes real-time. (One is timed using the IGT to kind of implicitly ban a glitch that makes true Any% kind of boring to run.)
It is screen-based, so you can treat each new room as a new level, and focus on saving time one room at a time. That means that you'll be getting PB after PB in the early learning process!
The main category has a huge leaderboard, because it is very accessible and a great place to start, but I really want people to start running Collectibles%. I am soon going to make a Beginner Route video of that category, which doesn't include the advanced skips shown in the top four times. Both categories are quite fun, because the gameplay is beautiful and fluid. Please give it a look! :)
102 Dalmatians on PC. Probably the easiest game I ever learned. Even a complete idiot like Cyberdemon531 could get a top time.
@Yoshipro101 No reason? Everything has a reason, boy. Cyberdemon doesn't take half the games he plays seriously. Also he spread the rumor that I was a pedo. Something that you ate up like the Cybersheep you are.
@Yajijy Oh no it's been very much public. Cyber started a rumor that, if in the wrong hands, can ruin my entire life. The justice system isn't this happy little fair place. I'm not going to sit by while my life is on the line because some autistic waste of life decides to use his power irresponsibly. He's no different from a bully. And his loyal sheep are even worse. Every one of them that I have had the displeasure of socializing with have turned out to be awful people. Great manipulators able to do mental gymnastics to justify every wrong thing they do. They're putting my life in jeopardy for a few laughs. This needs to stop.
"cybersheep" might be among the funnier things I've read on this forum.
Another quality battleon post and subsequent thread derailment!
@SuccintAndPunchy
LOL look again. Yoshipro101 derailed this thread. Not me. Perhaps you need to get glasses?
and in this exhibit of "The Weird Things Speedrunners Do", we have a thread for speedgame suggestions turn into a debate involving a speedrunner who is irrelevant to the topic post.
On a more relevant note, NES Ninja Gaiden, Super C, and Vice Project Doom are all fun speedgame you can easily cut the 20 in.
The Commander Keen games aren't that bad a grind to learn, and most of those are sub 10 minutes and 4 is sub 15.
another good short pc game is polarity, game is easily 5~ minutes once you get the hang of it.