I did a search and didn't find any topics on this game, so I'm making this post just to encourage people to check it out. It's a bit like a cross between Zelda and Castlevania: a side-scrolling game with subweapons, different dungeons, upgradeable equipment, and various useful and useless items.
The NES version is rather different from the MSX version (of which there is a
fan remake), but I still think it'd make a good run. There's an English patch which makes the game more playable in a non-TAS context; however, since a TAS would only see text in stores and at the end of the game, it's no big loss to use the Japanese version.
For a TAS, I see a few major issues:
* Route planning. The order in which you complete dungeons is restricted (each dungeon completed gives you the key to access the next dungeon), but there's a lot of important items in the castle proper to grab. Additionally, the dungeons have detours to collect various items that make the bossfights easier, which might be worth picking up if they don't take too long. The most relevant in a TAS would be the Pure Water, which halves the boss's life. The other two items give you infinite ammo in bossfights and increased defense; the former
might be useful but I really doubt the latter would be. You have to get these items once per dungeon, like the map/compass in Zelda.
* Ammo management. Ammo is plentiful in this game; enemies routinely drop 5-packs and you only ever need 1 to fire a subweapon. However, since you don't have to stop moving to use subweapons, unlike with your sword, the subweapons will probably see a lot of use. Not only that, the ceramic arrows can hit enemies multiple times, which really speeds fights up; not to mention they can give you a head start on breaking bricks, which would reduce the slowdown required to clear those barriers.
* Money management. Sadly, there's several items you have to buy in order to proceed. For example, to beat the first dungeon, you have to get 20 coins to buy a sword which can break bricks. There's a few places in the game where huge stashes of money are available, as well as some enemies that drop 50 coins instead of the default 1; it might be worth farming those as soon as possible, since money otherwise only drops 1 coin at a time (which, yes, means killing 20 enemies before getting that sword).
* Lag management. Also sadly, lag is pretty common, especially for bossfights or rooms with lots of enemies.
Finally, there's two characters you can play as, which you can switch between at any time: Popolon and Aphrodite. They have a few notable differences, but the most notable in my memory are that Popolon dies very quickly in water, but can control the height of his jump and can break blocks quickly; Aphrodite is the reverse. Shopkeepers will sometimes give more favorable prices to one or the other character, too.