Metal Gear Solid Peace Walker
is almost as good as the other games in the series. There are just two things that really hold it back.
1. There are very few human antagonists, so the boss fights have no personality (except the last one). Attack the tank. Attack the helicopter. And they've got few gimmicks or easter eggs or alternate methods. No-one is going to die of old age. The fights are still better than a normal games boss battle but all of them are avoid the attack patterns and Attack Its Weak Point For Massive Damage
2. After every mission it kicks you back into a menu and encourages you to go back and do base management. It saps tension and takes the flow out of the story. It's even more of a shame because the game and cutscenes make a thing of maintaining continuity, starting in the place the last mission ended in, showing travel. If it weren't for base management you would feel completely immersed in Snake's world.
These two issues stop this game being as good as Metal Gear 5 would be. But, providing you've played Metal Gear Solid 3
there is still a surprising amount of emotion to be found. In the last cutscene whilst not-Otacon was babbling about functional compensation and events were continuing to be ludicrously absurd and acting as if vague sciency words made it less absurd in fine Metal Gear Solid
tradition, I still found myself welling up a bit. I think the ridiculous nitpickyness of the franchise actually helps you become (despite yourself) more invested than you could in another game and allows it to pull off these endings that feel like they have so much more weight than other games.
There are things Peace Walker has improved upon though, it backloads it's story as badly as MGS 3
did, but a lot of the unnecessary cruft has been shortened down and confined to optional briefing files. Managing your base is fun and the gameplay really traps you into following Big Bosses dream and creating the antagonist organisation of the rest of the series. BB's journey from hero to anti-hero and ultimately villain is compelling and the theme of the story feels more useful than previous games. Cutting the gameplay into very definable chunks increases the likelihood you'll use a wider array of abilities to adapt, rather than simply restarting a checkpoint and its fun to sneak through a battlefield airlifting your enemies one by one to 'recruit' them