Obviously, I/O as an interface is the headliner here, but there are lots of other goodies to pay attention to, such as the "juicy main".
Small integers auto coercing into floats is a nice gift to game devs. It's nice that game dev is acknowledged as one of the niches Zig can target as I believe it could really thrive there due to how easily it can integrate with C & C++. Or, rather, more easily than the alternatives.