Okay, finally made it through this game. Can wash my hands of this one, even though it had great potential.
When you get to 1-3 or any other gold chest, aim for getting totems as much as you can. I can't quite remember how many choices you have when you start out (o-1-2-3?) but regardless, click "quit" after you've made your choices, just before you exit or "apply" the "Equip Yourself!" screen. When you start again, you will have retained any totems that you accumulated. I spent a lot of time on 1-3 getting all five totems, and then a bunch of the green Mayan ones that slow things down. In the early game, this slowing down plus the gold Hindu (more loot) and the blue Alien (exp.) will help out a lot. I just wish I could have seen how much each actually contributed.
Once you have this in hand, it's pretty easy. You can easily choose how many chests to open, and what kind, and how many enemies to fight, and how hard each attack will be.
Notes:
1) Even though your total totems on the start screen will reflect how many you got through the restarting strategy, they won't show up in-game until you exit properly with at least one in that category. That is, if you got two Mayan totems and clicked the exit "x" for the equip screens, now you'll have a Mayan icon in the upper left with "x2" shown. Not sure how much this affects the effects. Once you get 10 or more, the second digit will be cut off -- e.g., 15 totems will show as "x1" and 24 totems will show as "x2"; just kind of annoying.
2) I believe you're capped at level 20, which I wish I would have known earlier. I would have played through much more quickly and not tried to level up early and so much. At any rate, I figured this out around 6-1, and from that point on, I just ran through the rooms clicking "0" enemies. Went really fast then, especially when I took the time to arrange the entrance and exit stairs next to each other.
3) The lightning scroll can wipe out lots of enemies at once, and they're easy to get. Great way to build up experience, but I had too much of a stockpile since I was planning on leveling up way past Level 20 ...
4) But the poison scroll might be best for the bosses; basically does double damage. That coupled with the late-game helps of the Viking and Dragon totems made even the final dragon boss fairly doable. A few healing scrolls wouldn't hurt, using them when the boss is frozen.
5) Wish there was more info on whether or not the Buff Weapon stacks, or what leveling up the Viking and Dragon totems does for attack levels or whatever.
Hope that helps!