Programming challenges

Games

Yay, gamification! Here’s a non-exhaustive list of programming games I’ve enjoyed.

Advent of Code [Any language]
A recurring advent calendar where each day in December presents your with two new problems to solve in any programming language (or even brute force if that’s your thing). Your reward is – apart from the everlasting honor – a nice animated ASCII scene. See [2015], [2016].
Elevator Saga [Javascript]
Program an elevator in Javascript.
CSS Grid Garden [CSS]
Well, the scope is pretty limited – learn how to use the CSS grid property – but it’s beautifully done and a great introduction to programming. Yeah, I said it, programming. There’s loops, ok?
CodinGame [Various languages

Other

Sites with a collection of programming challenges.

Hackerrank [Various languages]
A learning and competition community. Regularly posts time-limited competitions where you can compete for glory and points. Lots of languages.
Project Euler [Any language]
Mathematical and programmatical challenges
Code Wars [Various languages]
Small programming tasks with increasing difficulty levels.