Hello!
I’ve been making my own 2D platformer with unity for about 2 months now and want to spice up my levels. I’ve always loved the levels change in Thomas was alone and have been wandering about how to do it. I know Mike Bithell(creater of Thomas was alone) is not a good programmer and probably did something really easy to do it. If you guys have any advice please do !
http://makeagif.com/i/Y1OnAP here is example of it in Thomas was alone
http://makeagif.com/i/l2Wokr
For levels like the first gif where it’s forming around the player it’s probably a case of the player activating trigger colliders that run tweens on whichever blocks need to be moved. For instances like the second gif where ground sections are randomly moving I’d say it’s random tweening. The asset store has a bunch of free tween library’s to create similar easing effects.
Actually he’s a great developer. Anyone finishing an excellent game like that, I tip my hat to 
For levels that do things, I recommend you use the Unity animation system and set a small trigger based script to play them.