I've seen that difficulties in the board have weapon categories.

Each difficulty has its own set of weapons, so unless you can use a weapon set into another difficulty, there is no need to add those cases.

Furthermore, Normal and Hard also have different weapons:

Normal has single pistol + slow shotgun in its set Hard has akimbo pistol + fast shotgun in its set.

I've only played one of the dungeon casually and in terms of runs, but if there's a need for a new category / dungeon runs, feel free to ask for it.

There should be 2 / 3 more dungeons in the game. A 50F and a 99F at the very least.

For people playing on 1.02 with the coordinates and other information displayed, 1.021 patch can be found on this page: http://honya2.sakura.ne.jp/yuuyuutei/html/thhkj.htm

Only replace the files from 1.02 with the ones included in the download

1.021 does not seem to change anything else other than the display issue

The maker's site has 2 links on their site, but one is on melonbooks, so hard to find (if they still sell it): http://honya2.sakura.ne.jp/