The square box thing didn’t really bother me, especially as someone who just replayed the game on emulator a few weeks ago. I don’t think the level design of MPO is nearly as good as Peace Walker because the latter game had way more immediately accessible cover spots and more variety, or even remotely as good as V’s level design, which did everything I want levels in stealth action games to do. But there was structural distinction in each level, courtesy of the building layouts, the amount of different cover spots and the verticality in some maps like the Silo, Silo Entrance, Guest House, etc.
I gotta disagree about the streamlined controls too, since MPO makes you hold more buttons to do basic things like sneak around or shoot, whereas in MGS3, you just gotta hit square while you’re running and gunning.
The missions were hit or miss for me too. I didn’t mind the “reach the goal” side of things because that’s literally every MGS game that isn’t MGSV; the only game to have actual objectives to carry out in the whole series. The difference was that the other games masked that with cutscenes instead of the glowing goals of MPO.
No, what really bothered me about MPO’s missions was its shit-awful pacing. The way you constantly have to wait on reports or recruit more and more soldiers to put on spy teams for each map and play the guessing game before something finally happens and you can move onto the next story mission. I would’ve loved to have just cut out the middle man and let the game’s plot advance mission after mission. Or to have more main missions with objectives, like the one where you have to capture and interrogate an official who’s on patrol with a guard, or blowing shit up.
To me, the pacing really is the worst thing about the game, on top of the tedious recruitment system, overly busy control scheme and the limited item slots, especially in missions that force you to use C4 or TNT for the objective and leave you with one less item for a boss fight.
As for story, again, not why I play these games, but the game could’ve definitely afforded to have a proper epilogue instead of simply ending after Gene dies. It feels very Resident Evil-esque in its abruptness, so I’m not a huge fan of that either.
I do ultimately think the game is rock solid. Its foundation is very strong and lent itself to even better games down the road, with some elements still reigning better than its predecessors (mainly its boss fights being infinitely better than MPW’s and I’d say on par with V, but better for actually having villains and not “boss monsters”, as well as doing what I always wished MGS bosses would do in just having you up against a singular enemy you can run and hide from or face off directly against). It’s just one where there were some pretty questionable design choices and a clear dip in terms of budget compared to most MGS games.