[ducky285]

I say Metroid because they provide a nice level of difficulty and the transition to 3-D didn't suck when it had the potential for disaster. I hate shooters, but I love the Prime series. The 2-D games, particularly Super Metroid, manage to take a simple idea and make a fun and deep game out of it.

Each game sticks to some element of traditional Metroid gameplay, but they put enough variety in each version to make the game experience different every time. I also like the storylines, which is odd considering the storylines aren't that well developed. Metroid games tend to give the player a better overall experience and accomplishment upon completing it.

The big criticism of Metroid is that the series is formulaic, but the same could be said of Zelda. My biggest criticism of Zelda is not only the formulaic gameplay and the lack of any real difficulty. The puzzles are great, but they range from being fun and clever to annoying and frustrating.

Mario games don't stick to a strict formula, though they follow similar ideas. No two Mario games (barring SMB and SMB2 JP) can be said to play exactly the same whereas Zelda and Metroid games seem to be frequently guilty of this. The difference is that Mario games don't provide much in terms of difficulty, storyline, or depth. They're simple games to learn, which is why the franchise is so popular among casual gamers.