Learning from linear level design

I thought one of the best things about Lugaru was the freedom to try a level how you wanted to. This is a very different style from the more linear levels I designed while working on Darkest of Days (which just released a demo). Even though you have to make a smaller area look good in games that keep you fenced in, they require a lot more work for a few different reasons. The main problems with linear levels are designing barriers that are convincing, making the difficulty consistent and keeping the player's attention.

An example of detailed set dressing and pathing in Darkest of Days

Even though it seems simple at first, designing outdoor levels with believable paths is very hard. So hard, in fact, that most modern big budget games fail at it. In games like Gears of War 2 or the new Call of Duty game, you will find your bullet resistant super-soldier blocked by imposing obstacles such as a foot tall pile of rubble or tall grass. Even in these examples, it is a lot of work to place invisible barriers and add the art assets to identify to the player that the edge of the level is there.

An impassable barrier in CoD:WaW

Where you can go in games determines to a large extent your ways of handling a situation. There are levels in Darkest of Days that allowed more open solutions to combat, but just as often there is only one approach and a limited number of tactical options. This means that you have to make sure that that one approach is both easy enough and fun. In an open area, with clear objectives, robust AI and gameplay, you can count on the player to figure out a solution of their own. This puts more work onto the plate of the programmer, but makes level design a lot easier.

Lugaru has low detail but open level design

Commonly in linear games you are given limited options on how to play, and since it has to be easy enough for everyone, it is possible for a linear game to become boring. One common way to solve this is to have a lot of exciting stuff going on around you. This is usually done using scripted sequences, like having your in-game buddies running into a trap, or planes swooping overhead, or buildings collapsing. It takes a lot of work to make these sequences, and if the player doesn't see it, it is a complete waste. Often in games you will notice scripted sequences happening when you come through a door, or when you are getting out of an elevator, so the designer can be fairly sure of where you are looking. This can give a game a stilted feel, as if the game is waiting for you.

An unfinished Overgrowth level

Linear levels can be really fun, but for Overgrowth we are planning to avoid these labor intensive level design solutions in favor of allowing players more control. This forces the player to think about what they are doing, and allows them to explore what they personally like in the game. This means you can't keep them entertained with huge explosions (that always just seem to miss you) and complex in-game scripting, but the player is also more responsible for their own experience. It means that the in-game situations feel more real, and the player has more direct control over them.

Is it a good idea to go with more open level design, or maybe there are things from linear games that we should include?