I think you can use Multiwfn. Regarding to page 157 multiwfn manual : "In GAMESS-US, add AIMPAC=.TRUE. in $contrl section, when the task is finished, the generated .dat file in $scr environment variable will contain wavefunction information with the same format as .wfn file, extract and save them to a new file with “.wfn” prefix."

You can add "density" keyword in the TDDFT calculation,

then you can use .fchk file or .wfn file to generete .cube file.

For example to generate .cube file of electron density of excited state from .fchk file or .wfn file, you can use the following commands in multiwfn:

-" drag .wfn file"

-5 // Main function 5

-1 // electron density

-2 or 3 // medium or high quality grid

2 //save data to gaussian cube file in current folder.

Then you can visualize electron dentity in VMD or other programs.

Also, if you can use CPMD code and its results is good for your work, i think, perhaps CPMD can perform TDDFT calculations with total electron density (with (RHOOUT) or the ELECTROSTATIC POTENTIAL keyword). In this software density.cube file can be generated with cpmd2cube.x file.(regarding to manual cpmd section: 5.1.3).