Here is a game which should hopefully be a hybrid
between a slenderman game and amnesia.
The core concept of the game is that you are walking
around a cuboid whitish world (could still have stuff like
reflective water). There may be other 'abstract
humans'(much like you are) NPCs, but they
are just
featureless black figures moving from one place to
another with a purpose (to various parts of the world, or
chatting to another).
Your main objective in this world is to not die, and to
not die, you must not get caught by the 'blurr'. The blurr
is an organism that can take the same formo abstract
humans, or later on to better stalk you... consume other
humans causing them to lose their free will and form.
(Similar to why real fur looks more real, rather than
plastic fur.). You can tell that a 'human' is infected by
the blurr if they look blurry, and then eventually by their
behavior (weird repetitive behavior, as if it was trying
hard to imitate other humans).
However unlike real life objects being less defined the
further away they are, a 'blurr' will look super crisp at a
distance, but will rapidly become blurry and less defined
the closer it is to you. (Until the last second, where it
will suddenly become unblurry and shape shift tentacles
over you)
And for some reason, it really wants you.
To win, you can't just wait them out, you have to
actually get as close to them, without the blurr noticing,
and then using a special telescope bring the original
person into 'focus', dispelling the blurr. It will notice if its
being focused on, and attempt to fight back.
To get near, you need to blend in amongst the crowd of
NPCs. This is often easy to do in the first few levels with
chatting NPCs. However later on, this will be
dangerious... as the blurr will get more abilities like the
ability to temporarily suppress its blurry look.
In later stage, you will focus less on visual identification
of the monsters, and more of working out the behavior
of NPCs to see if they are hidden monsters.
(each level adds another monster)
Level 0: Unintelligent blurry blob. In a forest. Very
similar to slender man, but lamer.
Level 1: Can only control one human, zombie like. Very
obvious (green blurr)
Level 2: Less obvious color, more intelligent behavior
Level 3: It gains the ability to be somewhat stealthy, by
not being so blurry too fast (allowing them to be closer
to you).
Level 4: Gains the ability to temporarily suppress its
behavior, but can still be detected by its unnatural
behavior.
Level 5: Gains the ability to conduct teamwork (Have
one monster be obvious, while another monster
pretending to part of a crowd that the player can hid in.)
Level 6: (End game) the monster has the ability to infect
humans, and now the gamer will have to avoid humans
entirely very soon. It will be impossible to kill them all,
you will now need to escape from the city entirely, and
you are in the middle of the city.
p.s. A series of games sequels, could be about the life of
a person being chased by a blurr. Each game
representing when the person was a toddler, a preteen,
a teen, young adult, adult, and old age.
p.s.s Maybe you will be assisted by a special agency, or
maybe hunted down by special agents to hand you over
to the blurr so they could contain the infection.