This is a very good game and yet I'm also going to recommend AGAINST buying it. Definitely do not buy at full price, but at least wait for a discount. Reasons are the poor support for this game and the DLC practices.
Can a game developer stumble on a very good game design, purely by accident and really, really not know what makes their game good? I think it could happen and Gladius could be exhibit A.
So let's get the bad out of the way first:
1. There's a lot of overpriced DLC for this game and a lot of consists of some good, interesting units sold alongside with inexplicably bad or redundant units, spread across the different factions, including factions from other DLC. Some of the DLC is decent, when there's a also discount event, but you probably won't know which is which before hand, unless you really take the time to look into it.
2. All this time, while making and selling more and more DLC, the developers won't fix old bugs for this game.
3. The balance of this game is way off in many areas. A lot of units on the roster simply never get built when playing the game optimally or even just somewhat effectively, because they serve no role next to better units. For multiplayer it also matters that the different factions are very unequal in power.
This game is a highly inaccurate and very creative translation of the official Tabletop rules for Warhammer. It has no die rolls for hitting stuff and no wound points and no evasion and other basic stuff like that, but instead the damage that units can do to other units during their turn, is 100% predictable and shown to the player before the player commits to an action... and it works. Silly as it is, it works really well.
That predictabilty turns the turn-based, tactical part of the game into a type of puzzle, where the player needs to figure out the correct order of actions for their units. There's still a lot of uncertainty on the strategic level, due to the randomized maps and the fog of war hiding units, but from turn to turn, the game becomes a series of entertaining puzzles.
You can play on big, random maps with a lot of players or many computer controlled players, but what this game excels at, is quick, short sessions on small maps. You can also turtle at the beginning and draw the game out for top tier units to come into play and some players of this game even prefer that style, but you don't have to. The factions are also differentiated enough to keep new game sessions varied and interesting.
Many strategy games have a diplomatic layer and many game developers struggle and fail to make a decent script for the computer controlled players, so here the developers simply gave up and didn't include diplomacy and this turned out to be a good thing. A very good thing indeed, because it helps to make the game much more focussed, on the things it does do really well. (Later on, the same developer did include diplomacy in their newer game, Zephon and that part is just as wonky as you'd expect from games in this game genre).
The strategic and tactical computer scripts are also bad, but that's what massive bonusses for the AI factions and difficulty settings are for. The map and game settings are also varied enough for this game.
What also helps this game is everything, from strategy to tactics, happening on just one map, instead of seperate battle maps like in games such as Total War or Age of Wonders. There's a place for that too, but this game excels at short games and the integration both speeds things up and also makes every choice feel more connected.
City development, the game economy and the tech tree are also very simple for this game genre and again this turned out to be a very good thing. The tech tree in particular, offers meaningful choices, instead of a lot of tiny incremental bonusses, unlike most other turn-based strategy games.
All this helps to place the focus squarely on the turn-based combat and that's where all the interesting stuff happens. Most units have interesting abilities and specializations. Trying to make them work well together is the fun part.
