The Lost Mind of Dr. Brain/Pentode

Pentode is a minigame where symbols will queue up above a board and you place them in a grid bellow. Place a group of two to five symbols next to each other orthogonally and they will disappear as the clock moves forward.

You win the round when the clock has advanced far enough. And you lose if the queue fills up.

The main complication here is that you can't see the symbols queuing up. Instead Ratbone will read each symbol aloud for you. The second complication is that you most likely aren't familiar with the symbol set. You get to pick from four symbol sets: American Sign Language, Greek letters, Roman Numerals and elements from the atomic table.

Higher difficulties add blockers to the grid, shortens the maximum queue length, uses a bigger subset of the symbols each round and speed things up. Oh, and the last placed symbol in a matching group doesn't disappear anymore.

Strategy
If you know one of the symbol sets well, pick it. If not, try each of them out and see if you aren't underselling your knowledge.

Be on guard for similar looking symbols, the game likes to pick symbols that are confusable for each other.

When it comes to placement, avoid boxing yourself in. Establishing a general location for each symbol helps to avoid panic placement.

If you want to score higher, make larger groups by intentionally leaving the connecting middle symbol until last.