I bought the Introversion Humble Bundle
to play Aquaria on my 64-bit Ubuntu 11.04 system. Unfortunately the mouse did not work, to the point of making the game unplayable.
First of all it was not possible to change resolution, because the mouse pointer kept moving back to "no". Far more seriously, while in game the character kept moving towards up and left.
A long search on the net provided no clear answer; it seems some people have the same problem on Windows and OSX too. On ubuntu some suggest to disable the package "unclutter" to solve the issues, but I did not have that installed at all.
My solution to the problem was to modify the ~/.Aquaria/preferences/usersettings.xml
file. Using any text editor, change the line:
<JoystickEnabled on="1" />
<JoystickEnabled on="0" />
The game is now playable ps: this problem was the cause of a lot of frustration for me, so I registered on this forum to post it - sorry if it has been posted already.