An Additional Symmetry by Waterloo

This was an unusual puzzle. The 90-degree rotational symmetry meant that across and down directions were often confused. Four entries were the reverse of another four, so PORTED covered for DE TROP etc.  The position and orientation of the clue numbers meant that the completion of this puzzle was a bit of a chore and Gregson feels pity for the checker!

1 Played games, dropping first of subjects and changed course (6)
PORTED SPORTED less S (1st of subjects)
3 Clumsy person losing head, nearly late, knocker down of doors (6)
PETARD (A)PE + TARD(Y)
5 Spoke sequence before the end of song (4)
RUNG RUN (sequence) + G
6 Someone employed to fetch beer and pant? (6)
DRAWER 2 definitions (singular of pants!)
7 Page gets head in jumper at last (4)
LEAF FLEA (jumper) 1st letter to last
8 Miner not in NUM, perhaps, makes disastrous return in bold resistance (9)
FREE-RIDER DIRE reversed in FREE + R (resistance)
11 Good for Charlie escaping fuss with half week lining loft with rush (9)
GARRYOWEN G for C in CARRY-ON containing WE(ek)
12 Stratford grease - it absorbs energy (5)
SEAME E in SAME
14 Literary genre Coleridge started, with a work of his own (5)
CRIME C + RIME
15 Medium, for instance one left surrounded by letters describing David Cameron's position (6)
MEGILP EG + IL in MP
22 Take up fascist leader leaving German forest and open country (6)
OSMOSE OSWALD MOSELEY (fascist leader) less WALD & LEY; unfortunately Oswald spelt his name MOSLEY so the wordplay doesn’t work!
23 A dance cut short after one record (5)
ALPHA A LP + HA(y)
25 Catches horses with a piece of sugar (5)
SNAGS S + NAGS
26 Girl and boy like night sky (9)
STELLATED STELLA & TED
29 Movement involving cleaner cap on dons in Scotland (9)
TRENCHARD CHAR (cleaner) in TREND
30 Lithe creature dropping a clumsy idiot (4)
STOT STO(a)T
31 Cathedral city with time for southern fruit (6)
RENNET T for S in RENNES
32 Uncles switch thousands for supplements in Scotland (4)
EKES EMES (uncles) with K for M (both thousands)
34 Dish made from sausage with no herb and cereal with no topped grain (6)
SAUCER SAUSAGE less SAGE (herb) + CEREAL less (M)EAL
36 Suppresses the Spanish purposes, eliminating leader in Andalusia (6)
ELIDES EL + IDE(A)S
 
DOWN
2 Excessive data processing, including deliberately old-fashioned elements. It's not right (6, two words)
DE TROP (r)ETRO in DP (data processing)
4 Australian party joining service for settling source of wool (7)
ALPACAS  ALP (Australian Labour Party) + ACAS (Advisory, Conciliation and Arbitration Service)
9 Gilt colour mixed with touch of mauve, not cerise (6)
ORMOLU Anagram COLOUR less C(erise) plus M(auve)
10 Where canoes can go I fish with a spear - no fish around (7)
IGARAPÉ I + GAR (a fish) + A (s)PE(ar) less SAR (another fish!)
12 Regional drink where you can find shade locally (5)
SWALE SW (region) + ALE
13 Rattler, tail first, American ingredient to enhance flavour (8)
AMARACUS MARACA (last letter first) + US
14 Stamp the stripped hide (5)
CACHE CACHET (stamp) less T (the)
16 Altered march tune where you might face fire (8)
ARMCHAIR Anagram MARCH + AIR (tune)
17 Swallow gets ruffled after harvest (6)
INGEST IN (harvest) + Anagram GETS
18 He deserts Saxon leader for profit (6)
REWARD HEREWARD (the Wake) less HE
19 Note orange-brown colour at end of ear (6)
TENNER TENNÉ + (ea)R
20 Respectful (or disrespectful) greeting for one of three kings, perhaps (6)
HOMAGE HO + MAGE
21 Clear space always in bliss with no second of depression (8)
DAYLIGHT AY (always) in DELIGHT less E (2^nd letter of dEpression)
23 Saw a comically entertaining person before start of entertainment (5)
ADAGE A DAG + E
24 Variety of creepy-crawly - gosh! one old fruit holds eighty (8)
MYRIOPOD MY + I + O (old) + POD (fruit) containing R (80)
25 Sharp point, not overdone, backing up upright member (5)
STILE STILETTO less OTT (reversed)
27 Rapid runner in charge in short burst (7)
OSTRICH Anagram SHORT containing IC
28 Take down one pirate captain (6)
UNHOOK UN (one) + (Captain) HOOK
33 Dog found in old pass by country residence (7)
COTTAGE TAG (dog) in COTE
35 Make sure hat is put back inside clergyman's place (6)
SEDILE LID reversed in SEE