Hi

Im making a tactical fantasy rpg/management/survival game where you control a group of heroes set out on a journey. Lots of influences from Darkest dungeon and Battle brothers. Its good to have "civilized" enemy groups like goblins that can have different troop types, fortifications etc in each area.

My idea for 4 areas to traverse is this:

1. Temperate climate. Goblins and trolls and wolves to fight. Continue by travelling on with a caravan.
2. Still temperate but more dangerous. Maybe similar enemies I havent decided, maybe orcs (goblin-like but thougher)? Take a ship across the sea!
3. Desert. More undead, what else? Large lizards and scorpions? Maybe lizardmen (warhammer made them aztec-like but maybe they can be egyptian-like?) Take camel-caravan onwards.
4. Wastelands. Dry, hostile lands with lots of demons. The end-boss rules these lands, so corrupted humans (cult?) might work?

Any input? This is a bit similar to the diablo 2 setup (temperate -> desert -> jungle -> hell) but maybe that's not too bad?

In each area these are some dungeons scattered (like ruined temple, catacombs, caves, abandoned jail etc) so areas should not be too different to let me reuse some of these in several area settings...

For sections 1 and 2, there are many types of "temperate" terrain that are appropriate for different creatures: for example all combinations of plains, hills and mountains with grass, forest and barren (glaciers, rocks, lava fields, salt flats, etc.) plus swamps, lakes and rivers, etc. For instance, what humanoids are better suited for roles like ambushing in forests or marching along a road in large armies?

Example: the assorted places visited by the Fellowship in Lord of the Rings, particularly in the first part of the journey. It's all temperate climate in your classification, apart from the mild "wasteland" of Mordor.