Popular games such as Portal (physics puzzle), Super Mario Bros (jump and run), Legend of Zelda (adventure with minigames), or Halo (action) look quite different on the outside, but they have one thing in common. They were successful because they had "polish".
In a polished game, everything is of one piece. The rules and game interactions provide a consistent experience. The game provides all details needed for the solution, and leaves no plot holes that distract from the solution (also known as the "Chekov's Gun" principle). Players are never pulled out of the immersion. Whether a move is illegal or legal, there is an obvious in-game reason, no wordy explanations required.
Be careful not to water down your fun game idea by making one game "do everything, but better". Gameplay does not progressively become better every time you add another cool gimmick. Ask your test players what helped them most, and what misled them most. Polish your game by identifying the fun areas and putting them in front and center. Drop distractions.
Different types of challenges appeal to different players. Optimally, you focus on one type of challenge. Here are some common examples:
Some games require hand-eye coordination and fast reflexes
Other games can only be solved with patience and logic
In some games you must find the perfect strategy and tactics
Other games can only be won with lateral thinking or pattern recognition
Similar to Charlie Sheen, different players consider different achievements "winning". Here are a few common groups of players who you may encounter:
Some players enjoy employing their reflexes in faction wars and coordinated teams. They expect to compete (and win) in duels against human players, with whichever weapon they collect during a match. Slow-paced brainteasers and predictable "artificially dumb" NPCs bore them to tears.
Other players enjoy taking on a role and training an avatar's skills. They expect to excel themselves every time they progress through another increasingly difficult quest. Game elements that cannot be measured, compared, and "min-maxed" do not appeal to them. Neither do they care about hand-eye coordination—after all, that's what the avatar trained Dexterity for!
Yet other players enjoy solo adventures, exploration, and brainteasers. They want to beat the game designers by solving a handcrafted puzzle. The last thing these players want is fellow human players spoiling the solution; nor do skills by proxy of an avatar have any value to them. Who needs an avatar if they can use their own problem-solving skills?
These are just exaggerated examples; the point is that games present vastly different challenges that do not mix well. Don't succumb to the temptation of squeezing too many types of challenges into one game. If you attempt to fulfill contradictory requirements, you risk losing the interest of all target groups. Or, as the famous saying by Antoine de Saint-Exupéry goes:
Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.