One of the themes of Kapla is the long skinny pieces, but the other is simply having large numbers of pieces, all exactly the same size and shape. Dr. Drew's not-so-skinny, not-so-long Discovery Blocks share that characteristic of a single block shape, as does my tower for today.
My blocks in today's tower are a smaller version of the unit block, at 15 mm x 30 mm x 60 mm. Dr. Drew's are 1/2"x2"x3", Kapla are 8 mm x 24 mm x 120 mm. In ratios, that is 1:2:4, 1:4:6, 1:3:15.
Dr. Drew's Discovery Blocks are still available as "pure" sets, but longer "planks" are also available, apparently a later acknowledgement of certain design and construction "imperatives."
Working with such a restricted subset of blocks on hand can add interesting variety to the block play experience, and is surely educational as well.