Labyrinth is not your average dungeon crawl, but instead an online riddle, with more than a few twists and turns to set it apart, and a horde of fiendish puzzles that just may trap you for eternity. The focus lies in code breaking and logic, the community and support features are outstanding, and many puzzles have multiple solutions. Can you emerge from this place victorious, treasure in hand?

Brown Dyed Hotel is a collection of puzzles that, as a whole, is one part discovery and one part riddle game, and it will surely give your gray matter a workout. Since each puzzle is slightly different than the one before it, the experience feels fresh and unique, if a bit short. There are only about 12 levels from what I could see. Some notes on the site hint at more, though.

The N riddle game is a URL-changing puzzle game that is somewhere in-between a wonderful, mentally stimulating journey and a migraine in the making. The first few levels are encouragingly easy and serve as a makeshift tutorial for the new player; soon, a comfortable rhythm of gradually increasing difficulty and clever puzzling has been established. And then...BLAM! ...see for yourself.

Tonypa is back with a new puzzle game and this one will surely give your grey matter a work out. In the spirit of Web-based riddle games, Tercessrebmun (or Secret Numbers) is a Flash game in which you must figure out the password for each of the game's 30 levels. Each level presents a series of characters from which you must derive meaning and clues that point to a single numeric answer.

The Roomz is a point-and-click game with similarities to online riddle games along the lines of God Tower and Ouverture Facile. One key difference is that The Roomz has a slight adventure flavor to it and, as a result, is more interactive. Each room has a locked door and keypad. You must use clues inside the room to discover the password to get out. Move objects and use the magnifying glass to peer at the scenery in detail.

Ouverture Facile is French for "easy opening" and is an online puzzle/riddle game similar to Dumb: The Game and God Tower. Using a combination of flash, images and other media, you must gather clues to find the solution to each level. There are over 90 puzzles to solve, so you'd better get started...

An extraordinarily high-quality online puzzle game that brings in real-life events to give you clues on how to complete the levels. Sponsored by Microsoft and created in conjunction with 42 Entertainment, Vanishing Point is an excellent puzzler that plays as good as it looks.

An online puzzle game in the same vein as God Tower, Dumb: The Game and Not Pr0n. These lateral thinking Web games are the work of one apparently psychotic mind, Mark Lautman. In the first 16 puzzles alone, you'll come across binary code, a crossword puzzle, a word scramble, and a quote from... nevermind, that would give the answer away. What they lack in polish they more than make up in deviousness.

A rather ominous and forboding title for a mysterious game that just popped up a few days ago. Tag this one under "riddle" as it is an HTML-based puzzle game for which answers to on-screen riddles are entered as URLs into the address bar of your browser to advance. But time is ticking.

The Wicked and The Wicked Junior are two online riddle games similar to Dumb: The Game and God Tower. Created by Tay Wei Kiat, the puzzles have an uncanny knack of being so simple they're complex. The answers are usually right before your eyes, yet you'll find that each time you'll be stumped for half an hour.

Dumb: The Game is a free online puzzle/riddle game that requires only a browser to play. Much like God Tower and a bit like Not Pr0n, Dumb pits you against a series of riddles and puzzles armed with only your brain and Google. As you struggle through, you'll definitely feel at least a little bit dumb. Thankfully a bustling community of players are there feeling just as lost as you.

The Enigma Puzzle is a sequence of riddles played in the same way as other games like it: Each one of its levels presents an HTML page with clues that you must use to figure out how to get to the next one. Use any tool at your disposal, including a text editor, graphics program, calculator, media player, and especially your browser's View Source function. Now with new levels (34-50) available!

For those who prefer a bit of a mind-bender over an action oriented game, Ankh follows in the same footsteps as not pr0n, God Tower, and various other password puzzles. In fact, this game was created by the very same person who created not pr0n. With Ankh, the author used nicely rendered scenes from an upcoming 3D adventure game set in ancient Egypt as backdrops for the game.

Do you yearn for a game to challenge your massive intellect? Did you beat My Diamond Baby in a half-hour without cheating? Want something harder? Well, here it is: God Tower. This is the toughest puzzle game I've ever seen. I'm not going to lie to you; it's currently unbeaten. But that shouldn't be a problem for you, right?

Created by Philipp Lenssen, Games for the Brain is a series of almost 40 different puzzle games to exercise and challenge your brain. It's a remarkably well-designed site that features a good variety of puzzles to tickle your gray matter.