  This paper reviews the confinement-driven phase transitions, and the
prediction of superfluid phases with broken time-reversal or translational
symmetry in thin films. The new phases are a result of particle-hole coherent
Andreev scattering processes that create quasiparticle states with energies
inside the superconducting gap. These states cause profound restructuring of
the low-energy spectrum in the surface region of several coherence lengths
$\xi_0$ with large spatial variations of the superconducting order parameter.
In confined geometry, such as slabs, films, pores, or nano-dots, with one or
more physical dimensions $D \sim 10\xi_0$, Andreev bound states can dominate
properties of the superfluid phases, leading to modified experimental
signatures. They can dramatically change the energy landscape, and drive
transitions into new superfluid phases, that are typically unstable in the bulk
superfluid. On the examples of single-component singlet d-wave superconductor,
and triplet multi-component superfluid $^3$He I show how properties of
condensed phases in restricted geometry depend on the order parameter
structure. I will highlight the connection between Andreev bound states and
confinement-stabilized phases with additional broken symmetries, describe
recent progress and open questions in theoretical and experimental
investigation of superfluids in confined geometry.
