The prototype of the game should
include as many object, Levelcomplexity and paralel running skripts to simulate
the planned game.
This could be done using primitive dummy-objects with the skinsize and polys
as the finished objects are planned.
The same for the level (just some random garbage of blocks and models)
and some loops in the skript that calculate dummycalculations.

This prototype should note the restrictions for the later game then.
(Like:
I get 30FPS on my avarage testmachine, using
up to 200 Objects with each 3 looping skriptfunctions, and a Level with
1000 blocks and 30MB of Texture.
)
The prototype is still an estimate, but it is better to see it running than some
paper-estimations.

So the developmentteam knows the restriction of how many objects
the levels can contain, how complex they can be before developing them,
without guessing all the time...


There also needs to be a strict analysis of the targetmachine.
-who is my targetgroup (ranging from "Shooter Freaks", to "Granddad wants to play A casual Pokergame with his pentium 2")
-what is the low-end machine of the targetgroup at the time of release
-what is the high-end machine of the targetgroup (not of some few freaks)
-does the game run on the at least 90% of the machines on my planned target group.
(not reuqiering certain shader extensions to run the game , if the new casual Tetris game will
require a hig-end computer)