Every tower now has a detail page, where you can look up stats and further info, that the game itself doesn't provide. Thanks @TheMarine for the suggestion!
You can access tower details by clicking the image in the towers overview. For instance, here is a Dandelion.
Right now it shows the damage progression of the tower from level 1 to level 99. I will certainly add more stuff to that page over time. Next on the roadmap would be a history of all balancing changes of every card.
If you're missing some stats or have further suggestions, please hit me! :-)