Well said on all points. (I would say that Jenga still has a single point of responsibility, but I digress.) I've adapted this take on the system for my second submission, which is a lot more flexible when it comes to target numbers and failing a roll. Basically, we've got variable targets, multiple targets per prompt (on many, but not all) prompts, and failing to meet the prompt just means a less favorable outcome, rather than certain death. While I'm sure that each individual target number can still be optimized for, if one wants to play the spreadsheet game, the larger variance should mean that most of the problems we've discussed can be avoided.