No dialogue webs. No cutscenes or momentary camera events. No optional objectives. Only a single, central path through the mission. A limit of eight scenes, one of which must be sacrificed every time you wish to toggle item/NPC activities and visibilities. No 'supported' indoor areas. Makeshift indoor areas being a big pain to make, and often interfering with the AIs ability to move and interact. No way to make an object no-collide. Multi-mouthed beings still only use one mouth to attack/speak with.
And to make matters worse, i've got a big mental block for adventures after barely making a single one, which I don't feel I did well enough on. xP
At least the GAprop thing is being worked on...