block placement/removal timers

	currently block placement and removal is instantaneous. it should
	actually take some time to place and remove a block. with
	removal timing depending on the tool used to remove the block

composite entity animations

	complex entities are made up of part which have their own local
	transform that can be animated (like e.g. an arm or head)

textures

	do I need to say anything? :)

command line

	usefull for development and later on world administration

font rendering

	mostly for labelled blocks and some ui elements

networking

	exchange of chunks and entities

persistence

	unloaded chunks should be saved to disk and restored when they
	are loaded again

launcher ui

	select or create a world with configurable parameters

entity ai

	pathfinding, chase and roam states

(block) lighting

	light levels are roughtly implemented. the shader has to be
	adjusted so they actually have an impact on the resulting color

gravity

	maybe like light levels? should also store a direction with it in
	that case. also, global gravity may be a world option.

block attributes

	when blocks are not just a solid rock of color, attributes may
	become interesting. like labels on signs and contents of
	containers

chunk traversal

	maybe the chunk loader should keep an index of interesting, if not
	all chunks by position, possibly base-relative

transparency (blocks and entities)

	transparent blocks because awesome

world generator that is not boring

	maybe divide into biomes and add special features like
	settlements, ruins, all kinds of interesting stuff