Take a look at this table for Heboris MINI. http://www.tetrisconcept.com/wiki/index.php?title=MINI Anyhow, if you notice though, the difficulty of many modes in Heboris gets progressively harder and doesn't cap out until a very extreme point. Endless is not necessary at all. Finishing the hardest modes are accomplishments in themselves.
hah ya i think the solo play modes get pretty crazy the practice modes are even crazier is it even possible to do well on oobaka
