I don't think that current top end mobiles have enough ram & cpu to survive a single game of terratech (with all the particle effect issues that are happening in all versions (perhaps is payload can fix the particle lifetime issues then it might be possible)
given the large number of L O O O N N N G term bugs that are still in the game from earlier in the beta computer versions(ie long before the consoles and switches), creating a whole new 'lite' version is highly unlikely to happen
The biggest performance bottle-neck in TerraTech is by far on the CPU.
The amount of information it has to process is immense. Every block has it's own physics, and when there are sometimes thousands of blocks on the screen at one time, with each block doing something different, there are a LOT of calculations to be made.
By modern standards the graphics in TerraTech are pretty simple, most Smartphones would be able to handle the graphics alone, but when you factor in all the processing, it doesn't look so likely.
So hopefully one day when Smartphones catch up with the CPU benchmark for TT we could look into something like this.