These are the packages that would be merged, in order:

Calculating dependencies ...

!!! Problem resolving dependencies for =games-util/gamemode-1.8.1
 done!
Dependency resolution took 0.82 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=games-util/gamemode-1.8.1" has unmet requirements.
- games-util/gamemode-1.8.1::gentoo USE="-elogind (-systemd)"

  The following REQUIRED_USE flag constraints are unsatisfied:
    exactly-one-of ( systemd elogind )

  The above constraints are a subset of the following complete expression:
    exactly-one-of ( systemd elogind ) any-of ( abi_x86_32 abi_x86_64 )