Aquaria is a sidescrolling undersea fantasy adventure game. The program is a hallmark of indie game developer success, featured alongside Braid and World of Goo as a recurring inclusion in the esteemed Humble Indie Bundle. It was developed as a onetime collaboration by Alec Holowka and Derek Yu under the moniker "Bit Blot", and published on the Mac by Ambrosia Software.
The gameplay of Aquaria is primarily combat-oriented, with platforming and puzzle elements in the mix. The linear storyline does nothing to hinder the feeling that the player is adventuring in a vast world. As the player enables new abilities with the game's progression, previously blocked-off territory is opened up, making even familiar locations new again. Experimental combinations of inventory items is also encouraged, and may result in a particularly performance-enhancing recipe. The cherry on top is that at least one total conversion mod based in the game world is available, expanding the experience further still.
Something about the cutout style of character animation used throughout Aquaria bothers me, although I can't place my finger on what exactly - the characters just don't quite feel believable to me. The game art is gorgeous as a whole, with parallax scrolling and a variety of environments emphasized by the iPod-worthy soundtrack.