Object "active", Action possible, Object "not active", Action impossible, Rollover

Hello the community, I would like to create a kind of automatic rollover, a “menu” who highlight an object for a while and if there’s no action from the user, the next object is highlighted, etc… The goal is to make a choice in a menu with only one keystroke, for exemple “Enter”. But the same key will be used for all items of the menu, it as to work only if the object is seen as “Active”. By “Active” I mean he can have a different size and colour for exemple, or be seen or not, or be squarred by a coloured edge, no matter, can you help me to find a clean way. I’ve play with Game Logic, read the forum, but did’nt found.
A prehistoric man who started 3d in 1989 with sculpt4D on Amiga. Blenderer since the first release but BGE newbie.