  We review the main results of the study of the Standard model propagating in
two universal extra dimensions. Gauge bosons give rise to heavy spin-1 and
spin-0 particles. The latter constitute the lightest Kaluza-Klein (KK) particle
in the level (1,0). The level (1,1) can be s-channel produced. The main signals
at the Tevatron and the LHC will be several $t\bar t$ resonances.
