diff --git a/tetris/block.py b/tetris/block.py
new file mode 100644
index 0000000..7055dfc
--- /dev/null
+++ b/tetris/block.py
@@ -0,0 +1,10 @@
+class Block:
+    """A Block represents a single square on the Tetris board. 
+    Blocks are part of a Piece while they are 'alive'.
+    """
+    character = "X"
+    color = "blue"
+    alive = True
+
+    def __init__(self, position):
+        self.position = position
diff --git a/tetris/game.py b/tetris/game.py
new file mode 100644
index 0000000..32cab79
--- /dev/null
+++ b/tetris/game.py
@@ -0,0 +1,7 @@
+from retro.game import Game
+from manager import Manager
+
+agents = [Manager()]
+state = {'level': 1}
+game = Game(agents, state, board_size=(20, 20), debug=True)
+game.play()
diff --git a/tetris/manager.py b/tetris/manager.py
new file mode 100644
index 0000000..6629dfd
--- /dev/null
+++ b/tetris/manager.py
@@ -0,0 +1,24 @@
+from piece import Piece, PIECE_DEFINITIONS
+from random import choice
+from retro.errors import AgentNotFoundByName
+
+class Manager:
+    """The Manager takes care of stuff that isn't anyone else's responsibility:
+    - Create a Piece whenever none exists.
+    - Clear full rows of Blocks (and move other Blocks down).
+    - End the game when the Blocks pile up all the way.
+    """
+    display = False
+
+    def play_turn(self, game):
+        try:
+            game.get_agent_by_name("piece")
+        except AgentNotFoundByName:
+            self.create_piece(game)
+
+    def create_piece(self, game):
+        width, height = game.board_size
+        piece = Piece((width//2, 2), game, choice(PIECE_DEFINITIONS))
+        game.add_agent(piece)
+
+
diff --git a/tetris/piece.py b/tetris/piece.py
new file mode 100644
index 0000000..beddd0a
--- /dev/null
+++ b/tetris/piece.py
@@ -0,0 +1,100 @@
+from block import Block
+
+PIECE_DEFINITIONS = [
+    [(-1, 0), (0, 0), (1, 0), (2, 0)],
+    [(0, 0), (1, 0), (0, 1), (1, 1)],
+]
+
+class Piece:
+    """A Piece is a group of blocks which are 'alive': 
+    They fall and the player can rotate or move them.
+    A Piece is created with a position, the game, and a list of block_offsets, 
+    each of which represents the location of one of the Piece's 
+    Blocks relative to the Piece position.
+    """
+    name = "piece"
+    display = False
+
+    def __init__(self, position, game, block_offsets):
+        self.position = position
+        self.blocks = {}
+        for offset in block_offsets:
+            self.create_block(game, offset)
+
+    def handle_keystroke(self, keystroke, game):
+        x, y = self.position
+        if keystroke.name == "KEY_LEFT":
+            new_position = (x - 1, y)
+            if self.can_move_to(new_position, game):
+                self.move_to(new_position)
+        elif keystroke.name == "KEY_RIGHT": 
+            new_position = (x + 1, y)
+            if self.can_move_to(new_position, game):
+                self.move_to(new_position)
+
+    def play_turn(self, game):
+        if self.should_fall(game):
+            self.fall(game)
+
+    def should_fall(self, game):
+        """Determines whether the piece should fall.
+        Currently, the Piece falls every third turn. 
+        In the future, the Piece should fall slowly at first, and 
+        then should fall faster at higher levels.
+        """
+        return game.turn_number % 3 == 0
+
+    def fall(self, game):
+        x, y = self.position
+        falling_position = (x, y + 1)
+        if self.can_move_to(falling_position, game):
+            self.move_to(falling_position)
+        else:
+            self.destroy(game)
+
+    def can_move_to(self, new_position, game):
+        """Checks whether the Piece can move to a new position.
+        For every one of the Piece's Blocks, finds where that block
+        would be after the move, and checks whether there are any dead agents
+        already there (live agents would be Blocks which are part of this Piece, 
+        not a problem since they'll be moving too).
+        """
+        x, y = new_position
+        agents_by_position = game.get_agents_by_position()
+        for offset in self.blocks.keys():
+            ox, oy = offset
+            new_block_position = (x+ox, y+oy)
+            if not game.on_board(new_block_position):
+                return False
+            for agent in agents_by_position[new_block_position]:
+                if not agent.alive:
+                    return False
+        return True
+
+    def move_to(self, position):
+        """Move to position and updates positions of Blocks.
+        """
+        x, y = position
+        self.position = position
+        for offset, block in self.blocks.items():
+            ox, oy = offset
+            block.position = (x + ox, y + oy)
+
+    def create_block(self, game, offset):
+        x, y = self.position
+        ox, oy = offset
+        block = Block((x + ox, y + oy))
+        self.blocks[offset] = block
+        game.add_agent(block)
+
+    def destroy(self, game):
+        """Causes the Piece to destroy itself. 
+        All the Blocks are set to dead.
+        """
+        for block in self.blocks.values():
+            block.alive = False
+        game.remove_agent(self)
+        
+
+        
+
diff --git a/tetris/planning.jpg b/tetris/planning.jpg
new file mode 100644
index 0000000..43bd614
Binary files /dev/null and b/tetris/planning.jpg differ
diff --git a/tetris/poetry.lock b/tetris/poetry.lock
new file mode 100644
index 0000000..83da853
--- /dev/null
+++ b/tetris/poetry.lock
@@ -0,0 +1,91 @@
+# This file is automatically @generated by Poetry 2.1.3 and should not be changed by hand.
+
+[[package]]
+name = "ansicon"
+version = "1.89.0"
+description = "Python wrapper for loading Jason Hood's ANSICON"
+optional = false
+python-versions = "*"
+groups = ["main"]
+markers = "platform_system == \"Windows\""
+files = [
+    {file = "ansicon-1.89.0-py2.py3-none-any.whl", hash = "sha256:f1def52d17f65c2c9682cf8370c03f541f410c1752d6a14029f97318e4b9dfec"},
+    {file = "ansicon-1.89.0.tar.gz", hash = "sha256:e4d039def5768a47e4afec8e89e83ec3ae5a26bf00ad851f914d1240b444d2b1"},
+]
+
+[[package]]
+name = "blessed"
+version = "1.20.0"
+description = "Easy, practical library for making terminal apps, by providing an elegant, well-documented interface to Colors, Keyboard input, and screen Positioning capabilities."
+optional = false
+python-versions = ">=2.7"
+groups = ["main"]
+files = [
+    {file = "blessed-1.20.0-py2.py3-none-any.whl", hash = "sha256:0c542922586a265e699188e52d5f5ac5ec0dd517e5a1041d90d2bbf23f906058"},
+    {file = "blessed-1.20.0.tar.gz", hash = "sha256:2cdd67f8746e048f00df47a2880f4d6acbcdb399031b604e34ba8f71d5787680"},
+]
+
+[package.dependencies]
+jinxed = {version = ">=1.1.0", markers = "platform_system == \"Windows\""}
+six = ">=1.9.0"
+wcwidth = ">=0.1.4"
+
+[[package]]
+name = "jinxed"
+version = "1.3.0"
+description = "Jinxed Terminal Library"
+optional = false
+python-versions = "*"
+groups = ["main"]
+markers = "platform_system == \"Windows\""
+files = [
+    {file = "jinxed-1.3.0-py2.py3-none-any.whl", hash = "sha256:b993189f39dc2d7504d802152671535b06d380b26d78070559551cbf92df4fc5"},
+    {file = "jinxed-1.3.0.tar.gz", hash = "sha256:1593124b18a41b7a3da3b078471442e51dbad3d77b4d4f2b0c26ab6f7d660dbf"},
+]
+
+[package.dependencies]
+ansicon = {version = "*", markers = "platform_system == \"Windows\""}
+
+[[package]]
+name = "retro-games"
+version = "1.1.3"
+description = "A simple framework for Terminal-based games"
+optional = false
+python-versions = "<4.0,>=3.10"
+groups = ["main"]
+files = [
+    {file = "retro_games-1.1.3-py3-none-any.whl", hash = "sha256:4bdd27241b5cb3ee72e69a042d301ff58df2a2ade7e3c29400a538fa54e30148"},
+    {file = "retro_games-1.1.3.tar.gz", hash = "sha256:4f91ff725e551820aa4e30c12c0264e2da41967ed34252122b7136bc2a8ed311"},
+]
+
+[package.dependencies]
+blessed = ">=1.20.0,<2.0.0"
+
+[[package]]
+name = "six"
+version = "1.17.0"
+description = "Python 2 and 3 compatibility utilities"
+optional = false
+python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,>=2.7"
+groups = ["main"]
+files = [
+    {file = "six-1.17.0-py2.py3-none-any.whl", hash = "sha256:4721f391ed90541fddacab5acf947aa0d3dc7d27b2e1e8eda2be8970586c3274"},
+    {file = "six-1.17.0.tar.gz", hash = "sha256:ff70335d468e7eb6ec65b95b99d3a2836546063f63acc5171de367e834932a81"},
+]
+
+[[package]]
+name = "wcwidth"
+version = "0.2.13"
+description = "Measures the displayed width of unicode strings in a terminal"
+optional = false
+python-versions = "*"
+groups = ["main"]
+files = [
+    {file = "wcwidth-0.2.13-py2.py3-none-any.whl", hash = "sha256:3da69048e4540d84af32131829ff948f1e022c1c6bdb8d6102117aac784f6859"},
+    {file = "wcwidth-0.2.13.tar.gz", hash = "sha256:72ea0c06399eb286d978fdedb6923a9eb47e1c486ce63e9b4e64fc18303972b5"},
+]
+
+[metadata]
+lock-version = "2.1"
+python-versions = ">=3.10,<4.0"
+content-hash = "03cc38c17964eb2c920ecf014cbfcf966c0c719418a127947b33382f086a0a6e"
diff --git a/tetris/proposal.md b/tetris/proposal.md
new file mode 100644
index 0000000..9a64528
--- /dev/null
+++ b/tetris/proposal.md
@@ -0,0 +1,27 @@
+## Game name
+
+Tessera
+
+## Vision
+
+Tessera takes classic Tetris and adds a light puzzle layer: arranged clears that match colors grant small bonuses, rewarding planning without changing the tight, fast arcade feel. It's worth making because it blends a familiar, addictive core with a gentle twist that increases depth for skilled players while staying approachable.
+
+## What the game will look like
+
+A clean, modern pixel/flat aesthetic with bright, readable tetromino colors on a dark background; the HUD shows next pieces, hold slot, score, level, and subtle particle effects on clears.
+
+## Player interaction
+
+Players use keyboard controls to move, rotate, soft/hard drop, and hold pieces; menus use simple mouse/keyboard navigation. The game emphasizes quick decision-making and responsive controls with a visible ghost piece to aid placement.
+
+## Core mechanics
+
+1. Falling tetromino placement and rotation — move and rotate pieces to fit them into the well.
+2. Line clearing and gravity — completed rows clear and the above rows shift down, possibly chaining combos.
+3. Hold and next-queue — store one piece and preview upcoming pieces to plan ahead.
+4. Color-match bonus (optional) — clearing lines where most blocks share a color grants small score/energy bonuses to encourage pattern play.
+
+## Milestone (first target)
+
+Implement the core game engine: represent the board and pieces, support spawning, movement, rotation, collision detection, locking, and single-line clearing so you can run a minimal playable loop and unit tests for the engine.
+
diff --git a/tetris/pyproject.toml b/tetris/pyproject.toml
new file mode 100644
index 0000000..7ce89ea
--- /dev/null
+++ b/tetris/pyproject.toml
@@ -0,0 +1,21 @@
+[project]
+name = "project-game"
+version = "0.1.0"
+description = ""
+authors = [
+    {name = "Chris Proctor",email = "chris@chrisproctor.net"}
+]
+license = {text = "MIT"}
+readme = "README.md"
+requires-python = ">=3.10,<4.0"
+dependencies = [
+    "retro-games (>=1.1.0,<2.0.0)"
+]
+
+
+[build-system]
+requires = ["poetry-core>=2.0.0,<3.0.0"]
+build-backend = "poetry.core.masonry.api"
+
+[tool.poetry]
+package-mode = false