thanks a lot

now everything is more clear

for the credits atribution can i use a readme.txt file that includes all  the info?

something like:

LPC Base tileset by Lanea Zimmerman (AKA Sharm) under CC-BY-SA3
 - dirt2.png
 - dirt.png
 - grass.png
 - holek.png
 - hole.png
Source: http://opengameart.org/content/liberated-pixel-cup-lpc-base-assets-sprit...

LPC Character templates by Stephen Challener (AKA Redshrike) under CC-BY-SA3
 - female_walkcycle.png
 - female_hurt.png
 - female_slash.png
 - female_spellcast.png
 - male_walkcycle.png
 - male_hurt.png
 - male_slash.png
 - male_spellcast.png
 - male_pants.png
 - male_hurt_pants.png
 - male_fall_down_pants.png
 - male_slash_pants.png
Source: http://opengameart.org/content/liberated-pixel-cup-lpc-base-assets-sprit...

LPC City by Outside Tuomo Untinen, Lanea Zimmerman (AKA Sharm) under CC-BY-SA3
 - city_outside.png
Source: http://opengameart.org/content/lpc-city-outside

LPC Male Clothing Variety Pack by Boom Shaka under CC-BY-SA3
 - male_pants_black.png
 - male_shirt_black.png
Source: http://opengameart.org/content/lpc-male-clothes-variety-pack

the user will be able to read this readme.txt file inside the game clicking the "Readme" button in the options menu

or its a better idea put the original credits.txt file that is included inside all lpc assets pack?