Tile manufacturers use a numerical value called a coefficient or friction, or COF, to rank how much traction a tile surface provides & in wet locations that number should be .60 or higher. manufacturers may not print the COF on the cartons & in that case it would be wise to ask about it. (Some building codes may even require a specific COF)

Some types of tile are too porous for use in a shower even if their size & texture seem appropriate. Natural clay pavers would let the water soak right through so they should be limited to dry areas.

Another factor is size, some floor tiles are available in up to 18×18, but that would be too large to conform to the slopes that are in most shower floor pans & would crack. I have seen larger tiles broken up & then laid on the floor in a mosaic fashion or you can use factory sheet mosaics that are flexible, form nicely to the floor pan & are quicker to install. Never use wall tiles in place of floor tile as they are not strong enough & will not last.