If you haven't enhanced your productivity enough with the enhancers in my previous two posts, try
Storm Winds. This one has you mounting cannons and guns to the side of a cliff to fend off wave after (really long) wave of enemies. You don't spend money to upgrade your weapons, but to repair them and buy new ones, and the weapons will gain levels as you have them in the field, so the challenge in logistics comes in trying to keep them repaired without wasting too much money. The challenge in the action sequences comes from simply hitting the enemies with the right weapons. They have a machine gun, which spray weak bullets; a cannon, which requires you to charge up and launch shells with the right power and trajectory; a sniper gun, which instantly hits the target but takes a while to reload; and more that you'll get when you can afford them. It seems to me that one of the starting weapons works much much better than the other, but maybe that just reflects on my style of play.
I should've noted it before, but all three of these productivity enhancers let you save and load your state. (Well, Flash Portal saves implicitly.) I very much like that in enhancers that take more than a half hour to beat.