when i try i get the following output

/home/user # apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
beneath-a-steel-sky
0 upgraded, 0 newly installed, 1 to remove and 13 not upgraded.
4 not fully installed or removed.
Need to get 0B of archives.
After unpacking 73.0MB disk space will be freed.
Do you want to continue [Y/n]? y
(Reading database ... 20267 files and directories currently installed.)
Removing beneath-a-steel-sky ...
dpkg: error processing beneath-a-steel-sky (--remove):
cannot remove `/usr/share/scummvm/beneath-a-steel-sky/sky.cpt': Read-only file system
Errors were encountered while processing:
beneath-a-steel-sky
E: Sub-process /usr/bin/dpkg returned an error code (1)
/home/user #