This weekend was Ludum Dare 21, the latest edition of the two-day development competition in which participants rapidly prototype games around a common theme -- this weekend's theme was "Escape", and the hobbyists, students, and indie devs joining in submitted over 500 entries.

One of the guys who took part in Ludum Dare 21 is particularly noteworthy for creating indie darling Minecraft -- Markus 'Notch' Persson whipped up a neat first-person adventure called Prelude of the Chambered, which you can play for free online or watch a full playthrough above (with some flickering).

The rest of the 500+ Ludum Dare 21 entries are listed and available to play here. You can even check out the competition blog, which features postmortems, timelapse videos, and insights behind the creation for many of the game written by participants.

And for even more indie games built over the weekend, have a look through the 67 titles submitted to Klik of the Month Klub #50, the monthly event that has people "write the best worst game that they can in two hours" with the Klik & Play toolkit.