Taken about 2 years but finally got all badges.
Grandmaster score chaser was the hardest one for me. Had to complete with 7 challenges to get it. Doom slayer was tough too but when I got the right build I absolutely smashed yog for it.
Nice! how did you complete doom slayer? with only the 1 challenge, or with multiple? I believe I completed doomslayer with only the necessary challenge and was able to do it rather easily since I've beaten the game with 6 challenges. Admittedly, I forgot that not destroying the demon spawners allows harder enemies to spawn. I was so confused to see the scorpions, and evil eyes around lol.
Yeah I only had badder bosses on for that one. And you're right, not easy with the extra mobs. I use a warden build and managed to get a good RoW run, loads of healing pots and a ring of furor+8 with a glaive, wand of regrowth with camouflage to keep away from everything.
Use doors to you advantage. Funnel enemies through them so that you can only be hit by one at a time.
Buy the Ankh at the shop and bless it with 20 water from your waterskin.
Identify all potions and scrolls as quickly as possible. Per area you get two strength potions and three upgrade scrolls. When there's a special trap room on a floor that floor will also have a potion to solve that room. Shops will have at least one scroll of remove curse, one mapping scroll and one health potion. When flies drop potions it's always a healing potion.
Never use a weapon or armor you're not strong enough for.
You have to use everything to your advantage. Seeds, stones, scrolls, the environment, everything. Circle around pillars or grass, and you'll land surprise hits, which guarantee a blow every time. Funnel enemies through doorways, don't get surrounded.
Any floor that has a puzzle room, such as needing to float to reach a chest or a room full of gas... that floor also has the exact Potion required to solve it.
Flies sometimes drop a potion. It will always be a healing one. Same for bats later on. Dew drops heal you.
You have to learn from every death, learn what every item can do. You will get there!
I'm still learning. The guys cruising a 9 challenge run still blow my mind.