Finished it.
Incredibly impressed by the game and Insomniac's fantastic level design, weapon design, enemy AI, graphics, story. The game does so many things right and yet this is just the start for awesome Insomniac FPS games.
Since I don't want to overhype it for those who haven't finished it and have it not be as good because they were expecting something beyond all expectations, I'm just going to spoiler text my glowing thoughts for those who've finished it already.
GoTY (been a crazy good year. I thought Okami would be an unbeatable GoTY, and then came Gears with it's excellent graphics and multipalyer with good single player, and now comes Resistance to top even that [will Zelda top even Resistance?]). Beyond just GoTY, I'll even say that personally I think this is the best FPS I've ever played. Until now my favorite FPS titles have been Half-life 1/2 and Halo 1/2 with everything else a good notch below. When I was about 75% through the game I came to realize that already Resistance was the best FPS I'd played on a console, even better than Halo :O But I still thought there's no way it could take the crown from Half-life. But by the end, the battles which were SO INTENSE (oh man in that walk up the tower at the end my heart was racing as I had 1 bar of health left and did not want to die and redo it all. I played sooo careful and well and luckily got through all that in one run. But wow it was crazy.), and the way the story was told both actively with the cutscenes and subtlely with the notes (cloven) and the hinting along the way about the American aspect...it was all so well done.
It had the architecture and interesting story of Half-life (though the characters were a bit underdeveloped in comparison), combined with the incredible AI and firefights from Halo combined with the enemy variety of an action game rather than an FPS with the same 4 enemies the whole game. All these pieces merged together to become my new favorite FPS, and to think this is only the start. I can't even begin to imagine how amazing Resistance 2 could be.
PS. Robots rule
PSS. Spider tank vs. GOLIATH = AWESOME (mecha fans will go crazy)
Graphics - Though I was definitely underwhelmed at first, by the end of the game I do not have a single complaint about the visuals but rather just pure praise. There are moments when it was hard to even believe I was playing a game and not watching some gorgeous CG movie. This is often thanks to the just excellent animation that is beyond probably anything we've seen in an FPS before. Everything moves so smooth and CGish...it's just WOW. One part in particular topped even the best Visuals in Gears IMO.
Music - The weakest aspect of the game IMO. The music was ok, but after hearing Gears with it's amazing soundtrack, this was a tad bland. Voice acting was good though as were the sound effects.
AI - Holy crap! The AI here is the best you will see in an FPS outside Halo (maybe even as good as Halo?). By the end the enemies use awesome tactics and they're out there doing the same stuff you're doing. It's really crazy to see how they think and how different the same scenes can play out each time. Also makes the game HARD but in a good way.
Enemy Variety - Completely awesome. Tons of enemy's all with their own unique weapons. Insomniac does a good job mixing them up and keeping players on their toes. The 'major' enemies in particular are a sight to behold and very enjoyable to fight.
Story - Good stuff! I was talking to TheTrin and much of the plot is hidden in the game and left for the player to put together themselves. This actually makes the plot a lot more interesting and we were discussing some various theories.
Level Design - Fantastic. The pacing is perfect, the difficulty ramps up just right, the architecture gets better and better, the levels are filled with all sorts of neat little things that you just catch out of the glimpse of your eye and go "woah".
Weapon Variety - Couldn't ask for more. Having so many options let's you make your own way through each fight. Also low supply of ammo keeps you switching around and making use of everything to make it through.
Vehicles - What? Fun vehicle levels in an FPS? How could that be!? I'm not sure how they pulled it off but the vehicle parts are really fun and some are just plain AWESOME. I loved them all.
Length - Great game length, just the right amount for a full FPS. PLUS unlike any other FPS out there (that I can think of) you get 2nd play GOODIES so like say RE/DMC, you actually want to go through it all AGAIN Plus there's Multiplayer but I haven't really played it besides a lame one-hit kill match with 2ch clan people, so I won't comment.
Loading - Could be better. It's not that the loading is bad (10 seconds or so for a level that'll last 10-20 mins), but rather that the levels feel like a few sections (20 mins) and then a cutscene/loadscreen. Maybe in their next FPS Insomniac can do seamless transitions between levels
Overall, the game might be inspired by all the greatest FPS games out there, but there's nothing wrong with taking inspiration from the greats and build off that for your own unique game. Resistance has everything I could ever want in an FPS. It has very smart AI + a wide spectrum of enemies and guns + a GREAT physics engine; so that every battle plays out differently and firefights are always great fun. It has excellent atmosphere, great presentation, gorgeous levels and art, and a neat story w/solid characters; so the game is always engaging even when not in battles. For the single player campaign there really isn't a single flaw I can think of besides maybe not having a checkpoint at 2 or 3 of the longer/harder points, and less loading/longer levels between loads.
Single Player score (all I really care about in an FPS): 9.8/10; Worth buying a PS3 for. I think that once the PS3 gets in more hands and more people have time to play Resistance through to the end, word of mouth will get around and Resistance will be 'the' console FPS that all console FPS games (single player) will be judged by