I think the whole premise of this thread is plain crazy!
I play Terraria on consoles, mobiles and PC heavily and have done for a few years.
It looks very simple but in reality the game world is one of the most complex I have ever seen in a video game, perhaps with the exception of Minecraft - I wouldn't know though as I've never played Minecraft.
The game constantly tracks the state of a massive, proceduraly generated world in real time. It would probably take a stock A500 weeks just to carry out the maths required to generate the world. Once it's generated the entire world is stored in memory during gameplay, and constantly updated in real time to cope with changes to the terrain made by the player and the game's automated procedures like fluid dynamics and corruption.
On top of that the engine throws around hundreds of objects (enemies, projectiles and items) at a time - check out youtube videos of people who have hacked/modded the game (though still running on the same engine) to see what it is capable of - 100s of players simultaneously existing and interacting in the world, for example.
Sure the crafting system is fairly straighforward, and the mapping system COULD be replicated, with enough RAM and processing power, but you need something far outclassing an A500 to do it. In my opinion it would be easier to port something like a modern Call of Duty than Terraria, despite the apparently "primitive" look of Terraria.