Linux only, nostd, in about 2000 loc.
- ← move piece once to the left
 - → move piece once to the right
 - ↓ toggle soft drop (can't be held because terminals don't support release events)
 - X rotate piece
 - ESC pause game
 
Starting with -l or --level followed by a number starts the game at that level (max 999).
To build you'll need:
- Make
 - GNU As (doesn't have to be gnu, but must support GAS syntax)
 - ld
 
You should already have all that on any linux system
make buildBuilt binary will be called xttrs. The code doesn't link against any library so you should be able to run it from anywhere.
The best score per user is stored in $XDG_DATA_HOME/xttrs/best_score (defaults to $HOME/.local/share/xttrs/best_score).
The whole codebase is a huge mess with no conventions, probably a lot of stupid things, I'm still learning.
