To assist in the design and development of my own level based around a core mechanic, analysis of games with a similar premise would be a crucial reference point in assistance of overcoming the ''digital blankpage''.
The following games were chosen as reference points based on the fact that they introduce a core mechanic and explore/enable it through their respective level design.
Crysis equips the player with a primarily physics based enhancement of the standard FPS shooter logics. I.e Enhanced strength, speed and armor, along with the ability to complete become invisible - all of which are limited by energy.
With each ability the level design of Crysis allows the player to experiment and figure out their own approach to achieve mission completion. Example, a mix of cover and invisbility can allow the player to stealthily manouver and avoid combat. On the contrary, the player also can push their way through waves of enemies using the environment as a weapon with the assistance of specific abilities such as strength.
A prime example of this approach would be the first ''non-linear'' area of the game immediately after tutorialisation.
The player is introduced to a aethestically pleasing wide open area. The widening of an other wise straight path and placement of secondary objectives in a ''non-linear'' manner immediately creates a sense of openness; the game feels less linear than it really is.
In addition the level is filled with destructible buildings, vehicles and other interactable items (including red exploding barrels). Each one of these can single pieces can become a physics based weapon a player can use, using grab and enhanced strength mechanics combined.
Even with the larger scale, the player is still led to advance forward without getting lost via clearly visible paths/roads, enemy placement and other vehicles (of which they tend to be parked in such a way that they face the direction of the objective). A combination of all of the above allows the player to almost ''choose'' on how they want to complete the whole objective, along with multiple different ways of traversing the level and allowing for different kinds of playstyles (not restricting).
Mirrors Edge' main focus is all about freerunning, with it respectively being the games core mechanic. The game is a linear action-adventure, however even here the general world/level design desguises the blatant linearity by mixing open-air spaces with enclosed large construction areas.
https://www.youtube.com/watch?v=jmJDo-XVwvg
A core design element that enables and guides the player along the level is the use of rhythm and color. Sections of the level that will allow the player for a smooth parkour transition are highlighted with a highly saturated colour contrasting to the otherwise (brightly) shaded world. Following this sort of colour coding also leads the player along not only to overcome obstacles but also to progress further in general. The key is rhythm (of colour coding) and patterns.
