In the end, all you need to do is find five treasures from the temple, escape with them outside, and head back to the starting room; your score will double from 25 out of 50 to 50 out of 50. There is no victory message so you have to invent your own.
I ended up looking up two hints; one I regret checking, the other I do not.

From Mobygames.
The first thing I figured out from last time was the gargoyle. To give some context, here is what fighting the gargoyle is like. (I have added the > marks for clarity.)
YOU ARE IN A LARGE ROOM WHICH SMELLS OF DECAYING FLESH. THERE ARE EXITS NORTH AND SOUTH. THERE IS A HIDEOUS STONE GARGOYLE PERCHED ON A LEDGE ABOVE THE NORTH PASSAGE.
>N
THE GARGOYLE COMES TO LIFE AND JUMPS DOWN TO BLOCK YOUR WAY! THE CLAWS OF THE GARGOYLE RIP THROUGH YOUR ARM IN AN ATTEMPT TO REACH YOUR BODY!
>KILL GARGOYLE
BLOOD RUSHES FORTH AS YOU HAVE SLASHED THE GARGOYLE IN THE ARM! YOU DODGE THE GARGOYLE’S HORN.
>KILL GARGOYLE
BLOOD RUSHES FORTH AS YOU HAVE SLASHED THE GARGOYLE IN THE ARM! THE GARGOYLE LUNCHES AT YOUR FACE BUT YOU PULL BACK. HE BITES YOUR SHOULDER INSTEAD! YOU PASS OUT. WHEN YOU AWAKEN, YOU FIND YOURSELF CHAINED TO A BLOOD STAINED ALTAR. A PRIEST IS KNEELING OVER YOU WITH A KNIFE. IT LOOKS LIKE THIS IS IT. YOU’RE DEAD. TRY AGAIN.
There’s one item I didn’t mention, a candle, because I hadn’t played with it yet.
>LIGHT CANDLE WITH LAMP
THE CANDLE IS NOW BURNING, A SWEET SCENT PERMEATES THE ROOM. THE LIGHT FROM THE CANDLE SEEMS TO BE GROWING DIMMER.
If you stay nearby the “sweet scent” after you light it, eventually you fall over and die.
THE LIGHT FROM THE CANDLE SEEMS TO BE GROWING DIMMER. YOU PASS OUT.
The candle works on the gargoyle equally well! So you just need to light the candle, drop it with the gargoyle, leave for a bit, and wait.
A CANDLE IS BURNING DIMLY. THERE IS THE DEAD CARCASS OF AN UGLY GARGOYLE HERE. THE LIGHT FROM THE CANDLE SEEMS TO BE GROWING DIMMER.
Past the gargoyle is a treasure, a GOLDEN CHOPSTICK.
The second thing I solved in a meta-way. The manual mentions you can PUT THE —- UNDER THE —-. This implied to me UNDER worked as a preposition, so LOOK UNDER was a possible action.
I remembered the sacrificial altar from last time (where I fought the snake) seemed suspicious.
>EXAMINE ALTAR
THERE’S NOTHING SPECIAL ABOUT THE BLOOD STAINED ALTAR.
>LOOK UNDER ALTAR
UGH! WITH GREAT DIFFICULTY YOU MANAGE TO MOVE THE ALTAR AND YOU DISCOVER A SECRET PASSAGE.
The passage leads outside; since I had three treasures (the golden chopstick, a golden idol from the altar room, and the gold ring from last time that caused teleportation) I knew I just needed the last two in order to win.
Here is where I got horribly stuck. The hint I don’t regret checking at all is that there’s a hidden gem randomly placed somewhere on the map, so you have to EXAMINE ROOM in each and every room until you find it.
YOU ARE IN A DARK PASSAGE WAY WHICH SLOPES UP AND TO THE SOUTH.
>EXAMINE ROOM
YOU DISCOVER A PRECIOUS GEM HIDDEN IN A CREVICE.
The manual does not mention EXAMINE ROOM is even possible. I’ve seen it once before in Temple of the Sun, but there it was a command in the instructions and there are enough hidden objects it doesn’t take too long for the command to be useful. With Raaka-Tu I only found the gem after examining nearly every room in the game.
The “good” puzzle is at the vault, which I mentioned last time, but I’ll repeat the description of here:
YOU ARE IN A VAULT WITH A LARGE DOOR TO THE SOUTH. A BEJEWELED LEVER IS ON ONE WALL. THERE IS A PLAQUE ON THE WALL ABOVE THE LEVER. THE DOOR CLOSES BEHIND YOU.
Pulling the lever opens a trapdoor which kills the player via burial in gold dust. I tried various ways of moving the lever only briefly, or throwing something at it, but it does make some sense the lever wouldn’t react in that way (it’s meant to be a trap, after all).
Remember, our goal is simply to escape with the fifth treasure. What should you do? Assuming you’ve read this far, you know enough to solve the puzzle, so I’ll provide my map of the inside of the temple to give you time to think about it.
The lever is described as jeweled. The lever itself is a treasure. You can just take it!
GET LEVER
BEJEWELED LEVER TAKEN.
I think the fact BREAK LEVER doesn’t work isn’t quite fair, as the verb is unrecognized (although HIT LEVER works), but — I’d still give this puzzle a thumbs-up rather than thumbs-down.
As I said before, there’s no winning screen; to end, you just find the random jungle spot you started at and type SCORE.
OUT OF A POSSIBLE FIFTY, YOUR SCORE IS 50.

I used the Text to ASCII Art Generator to congratulate myself. Here’s some victory music to go with it.
Including the lore from the manual about leading a team of anthropologists, the player character was oddly amoral (I mean, moreso than usual). The original goal was to find a lost tribe for “research” but the actual plot of the game involves sneaking in and stealing their goods, including a golden idol. If we point to the group’s use of human sacrifice as justification, then why isn’t the plot to try to stop them, or get some authorities involved?
The setting attempts to mitigate the story being a generic treasure hunt, but I’d argue the plot exposed the weaknesses of relying on treasure hunts. We’ve had some decent stories in the mold now (Zork II likely the best) but the form which could previously be put out without pretense starts to seem outdated when more substantial plot and character are required. There was still some juice left in the idea, most prominently in Infocom’s game Infidel (1983, by Michael Berlyn and Patricia Fogleman) which leaned into the amorality as an essential part of the main character. (Incidentally, if you haven’t played Infidel, and ever plan to, do not read anything about it — not Jimmy Maher’s essay, nor even the Wikipedia page — until you’ve tried it.)
“Limit thy powerful greed” does make me think Arnstein was thinking — at least in a minor way — along the same lines as Berlyn.

The back cover of the game, from Figment Fly. I’d like to know who the artist is but they aren’t listed in the manual.
This is just an impression: it seems good games are starting to show up (apart from infocom and Scott Adams). It seems good IF designs practices began to permeate in the companies and amateurs. Yay! Eighties!!!
One of the fun things about having details on all the adventures up to this point is it’s possible to “step back” and really see the landscape. In some cases, like this one, individual authors are improving (this is most definitely superior to Haunted House, despite the EXAMINE ROOM puzzle) In others, the authors seem to be studying what came before and improving based on that (Hezarin).
And then there are some authors who are just starting out and it seems like they’ve only seen Adventure, so there’s still a “reset” … but not as much now?