Well I've played on a map called towertop and it has like flooding ,and the moon dropping from the sky. I kinda wanted to do something like that. Thanks if you can get to this
The water flooding was done via a func_water_analog, the moon falling was done with a train in the skybox (the impact with env_shake, particle effects and an ambient_generic). If you're refering to how I triggered the events at the start of each round I used a logic_case triggered on a new round (via a logic_auto) to select an event to be played (PickRandom). You could combine it with a logic_timer to have a random event triggered every so often. I hope that's answered all your questions, but if you have any more ask away (I didn't realise anybody still played towertop)!
i have another question is there a progame where its like rollercoaster tycoon and you just set props down and walls and stuff
For mapping with source games? No, its all brush based and you have to draw it out etc, Rct3 is much simpler Great game though