IMO, there doesn't need to be a sharp distinction between the two.

I've got a scheme I've been using in which everything is contained in a $universe hashref, which contains a set of game objects, which themselves contain plenty of hashrefs and/or arrayrefs for sub-objects as applicable.

Very conveniently, the entire state can be saved and reloaded as a basic vanilla data structure with Storable.

It is object oriented in the sense that each module of the project deals with a certain strata of the universe tree and each element in that layer is best thought of as an object. But the code is given the objects instead of the objects having the code.

There are few safety rails with this setup, and a bit of crossover between objects, but a little self control goes a long way and the freedom is wonderful when you don't have to deal with other people :).