What is Bird Sort: Song of Yggdrasil?
Bird Sort: Song of Yggdrasil is a free online sorting puzzle. Colorful songbirds are scattered across the branches of the World Tree, and you move them branch by branch until every flock of four matching birds is reunited and flies away. It wraps the classic branch-sorting formula in a four-act Norse mythology story: from the green meadows of Midgard to the dawn gate of Asgard, where the caged Sunbird Sólvinur waits for your final flock.
How to Play
- Tap a branch to lift its topmost bird. Frozen birds cannot be lifted yet.
- Tap another branch to perch the bird. It must be an empty branch, or a branch whose top bird is the same color.
- Complete a flock. Four matching birds on one branch fly away together — and thaw one layer of ice on every frozen bird.
- Clear every branch to finish the level. Finish in par moves to earn all three stars.
Rules at a Glance
| Rule | Detail |
|---|---|
| Branch capacity | 4 birds per branch |
| Legal landing | Empty branch, or matching top bird |
| Frozen birds | Cannot move; each completed flock thaws 1 layer |
| Flock completion | 4 same-colored birds fly away and free the branch |
| Stars | ≤ par moves: ★★★ · par+3: ★★ · otherwise ★ |
| Undo | 3 undos per level |
Why Bird Sort Stands Out
| Feature | Bird Sort: Song of Yggdrasil | Typical sort puzzles |
|---|---|---|
| Story | Four-act Norse saga with interludes | Level numbers only |
| Levels | 30 handcrafted + endless waves | Static set |
| Difficulty curve | 2 → 9 colors, ice layers 1 → 3 | Flat or random |
| Art | Painterly living tree, animated birds | Flat icons |
| Offline save | Progress & stars saved in browser | Often none |
Frequently Asked Questions
What is Bird Sort: Song of Yggdrasil?
Bird Sort: Song of Yggdrasil is a free online sorting puzzle. Colorful songbirds are scattered across the branches of the World Tree, and you move them branch by branch until every flock of four matching birds is reunited and flies away.
How do I move birds between branches?
Tap a branch to pick up its topmost bird, then tap another branch to drop it. A bird can land on an empty branch or on top of another bird of the same color. When four birds of one color share a branch, the flock is complete and they fly away together.
How do I free frozen birds?
From Act II onward, Loki seals some birds in ice. Frozen birds cannot be picked up, but every flock you complete sends a pulse of warmth through the tree that thaws one layer of ice from every frozen bird.
Is Bird Sort free and can I play it on my phone?
Yes. Bird Sort: Song of Yggdrasil is completely free, needs no download or sign-up, and runs in any modern browser on desktop, tablet and mobile with full touch support.
How many levels does Bird Sort have?
The story mode has 30 handcrafted levels across four realms of Norse mythology — Midgard, Alfheim, Jotunheim and Asgard — plus an endless mode with procedurally generated waves that keep getting harder.
Technical Notes
The game is a single self-contained page: original canvas artwork, WebAudio-synthesized sound, deterministic seeded levels verified solvable by a built-in solver, and local progress saving. No downloads, no accounts, no tracking — just tap and sort.