Hello Aleksej !
Tonight I finally took time to install SLiM v.1.3.5. Really cool, good idea! I love your cat; it looks like the one of my daugther. This will be one more reason for her to regret to still use MS Windows ;-)
The french message "Bienvenue à l'SliTaz ! is not correct. I modified lines #46 in /usr/share/slim/themes/cat_and_spider/strings and #49 in /usr/share/slim/themes/cat_and_spider/slim.theme like this w:fr Bienvenue sur %host !
Agree with mojo: rolling should deserve this wallpaper and your slim-theme-mascot, I really don't like the actual wallpaper.
By the way, why don't you place your packages on http://mirror.slitaz.org/packages/4.0/ ? Now I have to take care when I check for upgrades, TazPanel systematically proposes SLiM package v.1.3.2. Well not really important. Thanks for this work.