Let's face it: Anyone who's played games has played games in which you just go around and shoot everything that moves. That's been done to death. You've got to have a wider range of activities, and the player has to figure out what activities to use and when to use them. Let's go back to Halo for a good
example of this.
If you play Halo, you can play it much like the thousands of shooters that
came before it. That is, you can just shoot everything up. However, you can be cleverer about it, if you want to.
For example, instead of just stomping into an area and shooting up all the
aliens, Halo lets you sneak up on them while they sleep. Using your weapon as a club, you can kill the aliens by hitting them. It's possible to clear an entire large room of aliens by silently whopping them each on the back of the head. Another interesting thing about Halo is that you have constantly shifting
alliances during the game. Sometimes, it's best to let your enemies fight their enemies and just sneak on by without firing a shot.
It always increases the player's interest level if you provide multiple
approaches when confronting a situation in a game. For instance, there's one spot in Halo where you're crossing a long bridge-like structure. You can fight your way across it, take an elevator down to ground level, and then climb a pyramid. Or, if you're a bit smarter, you can sneak onto an air vehicle called a
banshee and fly over to the pyramid. But in order to do that, you have to get the invisibility cloak, which is quite a way back from the bridge.
Another approach to the bridge is to fight your way to the middle (or sneak there with the invisibility cloak), and then jump down onto one of the struts that hold up the pyramid structure. But to do so, you have to have good health and you have to have a weapon called a needler. The reason you want the
needler is that, as you're running down the strut to ground level, aliens are shooting at you. Because you need to concentrate on running down the narrow strut, you can't aim well. The needler is a heat-seeking weapon that doesn't require much aiming.
If you run down the strut fast enough, you can jump into a pit at the bottom. There you'll find a sniper rifle and a rocket launcher. You can grab those two weapons and go back up the strut. With the sniper rifle, you can kill all the aliens that shoot at you. With the rocket launcher, you can blow up the tank at the base of the pyramid. You can then run back down the strut and steal a
vehicle to take you up the pyramid.
The result of all of these game features is that you have the option of just blindly shooting your way through the game or thinking up better strategies. Games that allow the possibility of flexible thinking on the part of the player are much more fun.
One caution here: Making players think is not the same thing as making them guess your clever plot trick. An example will help clarify what I mean.
I once played a game in which the main character was a janitor on a starship. Of course, the starship was invaded by evil aliens and the rest of the crew killed (the janitor was sleeping in the broom closet). The aliens set the ship to blow itself up, so the hapless janitor needed to get off fast. To get him off the ship, you had to get him to open doors to the shuttle bay.
Tip
Giving players many ways to solve problems in games makes the games more fun. It also gives games a longer lifespan. People will play through your game again and again to try and find every possible way to solve each challenge.
At that time, it was normal to type text commands into games (mice weren't common yet). So to get the janitor to open the doors, you had to walk him into the proper control room and type a command that would make him push a button. Unfortunately, the designers of the game decided to be clever here and make the player guess the exact command that was required to get the janitor to push the button. I tried "Push button." No luck. Next I tried "Push door button," "Press button," "Press door button," and so on. It wasn't all that long before I was typing "Press that @#!$% button you stupid *%^$#!"
The people who made this game didn't understand that making players guess the designer's cute trick is not the same as making the player think. The
challenge should have been something like finding the card key that gave authorization to open the door (I found it lying on the floor). Making players guess the right set of words to get the door open made them focus on the game's interface, not on the game. That's not good game design.