I can't open it on Mac says 'developer needs to update it' do you plan on updating it? Bcause I really wanna play!
Sorry! It's made in an old version of Unity that can't be codesigned in the current version of Mac OS, so rebuilding won't fix it without building it in an entirely different version of the engine and taking on a pile of extra risks. Running the Windows version in a Wine bottle will probably work, though: https://winebottler.kronenberg.org/
In indie mac gaming, it is very very common for people to distribute unsigned mac games. We mac gamers have an easy way around that, which is a simple bash script (see below). All that is required to make it work is that it be rebuilt to 64bit OS X target, it is not necessary to update the actual version of OS X that it is targetting nor to properly codesign the bundle.
[[fixapp.command]]
```bash
if [[ $# -gt 0 ]]
then echo "...$1"
echo $1
else
echo "correct execution format: 'sudo fixapp.command ~/Applications/App.app"
fi
if [[ "$1" ]] ; then
echo "fixing app"
sudo chmod -R 755 $1
sudo xattr -dr com.apple.quarantine $1
echo "launching from app"
open $1
exit
else
echo "error"
fi
```