The pieces land where they land

Animals rain into a glass well and pile up like real objects, because they are
real objects — every one is a physics body that rolls, wedges and settles.
Nothing snaps to a grid. Nothing lines up neatly. Clear any three or more of the
same animal that are touching, and watch the whole pile collapse into the gap.

A round is twenty-eight seconds and a score target. Miss it and the run
is over.

Bombs do not care that you were in a hurry

Bombs and blocks fall in among the animals and cannot be matched. Click a bomb
and it costs you a life — and you only start with one. Blocks just sit there
taking up the space you needed.

The way out is to clear around them: any hazard caught in a clear goes
with it, and pays a defuse bonus. So the question stops being "where are three
of the same animal" and becomes "which three, and what do they take with them".

Miss entirely and you lose a slice of the clock. Clicking wildly is a strategy
that loses.

Ten rounds, then a decision

Clear round ten and you have beaten the game. Bank it and the win is yours.

Or push on into bonus rounds, where the targets keep climbing and the payout
grows every time — and the whole pot becomes the stake. Clear the next round and
it grows again. Fail it and you walk away with nothing, however far you got.
The choice comes back after every bonus round. It is entirely your fault
if you keep saying yes.

Two layers of upgrades

• Between rounds, spend the coins that round earned. Widen what counts
  as touching, make pairs count as a match, clear neighbouring colours too, buy
  back time, defuse more bombs. These last for the run and then they are gone.
  
• Between runs, spend tokens on permanent upgrades — more lives, longer
  rounds, a bigger shop, a head start on score. Respec is free and always
  available, because a build you are afraid to change is not a choice.

One permanent upgrade makes the game harder. Menagerie adds another
animal to the pool, which thins your odds on every single clear. There is an
achievement for beating the game with all of them in play. That is the only
reward, and it is the point.

Also

• 36 achievements, from your first cleared group to a long tail that will take
  a while
  
• Mouse only — one button, no keyboard, nothing to learn
  
• Colourblind mode puts a distinct shape on every animal
  
• Fullscreen or windowed, and it remembers which