izigame.me

It legitimately sucks that I have to do this, since I was so excited and down to get this DLC, yet from the moment I got it I got swamped. But at this point, having played it for a while, I'm just gonna say my piece on it.
Someone in another review stated that this DLC is feature bloat. They couldn't be more correct. Whereas Royalty provided an expansion on existing features plus a couple of new ones, Ideology provides an expansive list of new features with no actual coherence to old ones. It changes the pre-game setup from a short setup to a long schlog that ultimately asks, "how badly do you want to game this system?" and gives you a number of options on how to game that are exclusive to your choices with no actual opportunites to expand or evolve beyond them.
I'd make the argument that a couple of things in this DLC ought to be included in the base vanilla experience, if nothing else but to give players a leg to stand on and something to expect before diving right into this. Things like enslaving pawns (you could sell prisoners already in the vanilla game, so why not go whole hog?), sowing fungus gravel for nutrifungus as a crop option, and maybe having a leadership role in your colony - the kind of stuff that would more or less slot perfectly into the vanilla experience. Instead we have what's effectively an overdeveloped mod that doesn't feel like an optional choice, since many existing mods in the workshop are built to mesh themselves with the expansion.
One last thing I will mention, I feel like several of the memes are a bit too strict. Isolationist and Human Primacy I can understand, however tunneler requiring that fungus is preferred over other crops feels dumb, especially when with other memes you can freely alter some of the other precepts without consequence. Again, it feels very gamey and a disconnect from what base Rimworld has offered in the past, which is an effective storytelling experience in the form of a visually simplistic colony sim.
TL:DR - You do not need this DLC to enjoy the game, most of the features feel gamey and disconnected, and other reviewers who didn't care for it either have also pointed this out.