I've got a complaint for ya, the changing of the money system to the point system, and the weapon upgrades to the skill upgrades.
The progression of upgrades started awesome in RE4, then sled downhill more with each game. In RE4 it was extremely fun trying to figure out which guns you wanted to take vs the amount of space you had in your case. The merchant had so many different options of things you might want to bring along, not just lots of different weapons, but attachments for weapons, each one you had to value it's use vs the space it took up. You had to decide when it was worth it to buy more stuff or save for a bigger case, and which guns you should upgrade. Selling things was also a viable option. Ammo too. Say you decided to go the game without using the TMP, as i did my first time. Then, all ammo that you find for it you can convert to extra funds. Finding treasures was also an awesome factor into the game, they could be sold for high prices, and some you could decide if you wanted to wait and combine them or sell them early for a much needed upgrade.
RE5 didn't do it AS WELL, but it still did very nicely. You no longer had to play tetris with your inventory, and you had a case with unlimited space so you could give and take weapons between chapters. This was a bit dissapointing because i liked havin to make the hard space-usage decisions, and being able to expand my inventory. I also liked being able to equip very tangible addons to my weapons like the Red-9 and TMP stocks. This was also where they started you out with maximum health, instead of letting you upgrade it through yellow herbs, which I disliked because in RE4 finding yellow herbs was like an orgasm. The treasures could not be combined, so they turned into a gimmick, you might as well could have just replaced them with sums of cash and had the same exact thing.
RE4 and 5 both kept me on edge for the next weapon though, I distinctly remember how happy i felt when i found some of the new weapons, like an awesome childhood memory. Finding the shotgun in RE4 in the first village scene was just so climactic. It was exactly what you needed to blast your way out of that tight barricaded house, it was just an iconic find. In RE5 had some great ones too. Those silver cases, you remember those? Whenever i saw one of those, it was like running into one of the huge chests on Zelda, you just know something awesome is going to be inside. In both games, I was super stoked after finishing boss and mini-boss fights, because they'd always drop a very tangible sign of my accomplishment. Chainsaw infected in both games would give you something awesome to remember them by, (a ring i think), and El Gigante left a huge pile of money, 15,000 or so if i remember correctly. I would always thing "SHIIIIIIIET, you just bought my pistol some more firepower!" Speaking of firepower, that's also what RE4 and 5 did awesomely. Specific stats and upgrades for each weapon. In RE4, 1 power was the starting power of the first pistol, and based on that i would always calibrate my choices. You don't even know how amazed i was when i got my Red-9 to like 5 power, I was like, "each shot of this is going to blast them like 5 pistol shots all at once," and i felt it too very well, i could shoot an enemy like twice and he'd drop.
RE6 is just disappointing in comparison. There is virtually no inventory, just a list of items that you scroll through. Skill points progress your character, but i really don't feel much of a difference at all. The weapons all seem to blend into each other. Each campaign has different weapons, but i just don't see enough difference between the way they operate. I am just thinking "well, looks like i found the generic shotgun weapons of this campaign... oh and here is the generic machine gun weapon of this campaign." Bosses are now just something to kill so the story will progress, not something i want to unload into because i'm going to get an awesome reward. I guess what i'm trying to say is that RE4 felt like an awesome strategic shooter RPG, RE5 still was like that but not as much, and RE6 felt like an arcade style game; like if i played my save game and my neighbors, i wouldn't be able to tell the two apart.
it felt like i was in a movie, of a character i can control (of their actions) *or something like this 
