Interesting game design. Maybe it's frustrating being limited to five letter words, but otherwise engaging!

My high score is 3015, using mega-combinations like REMEMBERER, SISSYISH, ZOOZOO, SEERESSES, PEPPERIER, KINNIKINNICK, GREEGREE, ARRACACHA, SALSILLAS, EISEGESIS, TRINITRIN, KAWAKAWA, OIDIOID, ARREARAGE, COROCORO, RIRORIRO, CHICHI, SUSURRUS... but it didn't save!!! :-((

Once you reach a certain stage it becomes almost impossible to lose. At the end of my game it had taken ages so I just shot some chickens until I died. The key to "beating" this game (it doesn't have a final achievement you have to beat, it just goes on endlessly as far as I can see) is good familiarity with a Scrabble dictionary. Getting combinations using all 5 letters is great, but even using 2, 3 or 4 letters can do a lot of damage if you get the timings right and try to reuse letters. You'd be surprised how long a word you can make from just a few letters - google for "dcode longest word" to see what's possible! I've assigned a star rating to ones I think are worth always looking out for.

Powerful two-letter combos worth looking out for:
AD 5*: dadda
AM 5*: mamma
AN 5*: anana, annan
AT 5*: taata, tatta (also tata, atta if don't want 3rd A)
BE 6**: beebee (also bebe if don't want 3rd and 4th E)
BO 6**: booboo (also bobo if don't want 3rd and 4th O)
DE 6**: deeded
ES 5*: esses (also eses, esse, sees, sess if don't want 5th letter)
EW 6**: weewee
IL 5*: lilli
MU 6**: muumuu
OZ 6**: zoozoo

Powerful three-letter combos:
ABR 7*: barbara (also barbar, barba, barra if don't want extra letters)
ACH 7*: cachaca
ACR 8**: caracara
AES 8**: assesses
AFL 7*: alfalfa
AHL 7*: halalah
AHT 7*: tathata
AKW 8**: kawakawa
ART 7*: ratatat (also tartar if prefer 2nd R instead of 3rd A and T)
COR 8**: corocoro (also rococo if want fewer letters)
CSU 7*: succuss (also cuscus, succus if don't want 3rd S)
DIO 7*: oidioid (also iodid if don't want 2nd O or 3rd I)
EFO 7*: feoffee
EFR 8**: referrer (also referee, reefer, refer if want fewer letters)
EGR 8**: greegree
EIS 7*: sissies (also isseis, seises if want fewer letters)
ELS 7*: lessees (also lesses if don't want 3rd E)
ENT 7*: entente (also entete, if don't want 2nd N)
EPR 8**: pepperer (also pepper, peeper if want fewer letters)
ERS 9***: seeresses (also seeress, seers, etc if want fewer letters)
ERV 7*: reverer
GIN 7*: gigging (to target G), ginning (to target N, also inning to avoid 2nd G)
IKN 11***: kinnikinnik
IOR 8**: riroriro
RSU 8**: susurrus

Four-letter combos I used surprisingly frequently or which are very powerful:
ACHR 9**: arracacha
ACIM 8*: caimacam
ACHU 8*: cachucha
ACIT 7: atactic
AEGR 9*: arrearage (also eagerer if don't want 3rd R)
AEIR 7: arriere
AFIR 8*: riffraff
AGIP 6: agapai (surprisingly hard letters)
AIKM 8*: kaimakam
AIKR 8*: kakariki
AILM 8*: mammilla
AILP 9**: palilalia
AILS 9**: salsillas (also salsilla if don't want 3rd S)
AINR 8*: ranarian
AITW 7: waiata (also await if don't want 2nd A)
BCLO 8*: cocobolo
BEIR 8*: beriberi
BEMR 10***: rememberer (also remember, member etc if want fewer letters)
CDET 8*: detected
CDIO 7: coccoid (oidioid also a choice if don't want to use C)
CERT 7: erecter, reerect
CEHU 5*: heuch (surprisingly hard letters)
CHUY 5*: yucch (surprisingly hard letters)
CINU 6: uncini (surprisingly hard letters)
DEIL 7: diddled
DEIV 7: divided (to target D), divvied (more even spread)
DELP 7: peddled
EFIR 7: fierier
EGIS 9**: eisegesis, eisegeses
EHTY 8*: eyeteeth
EILM 8*: millieme (can also play as milleme to avoid second I)
EILS 8*: isleless
EIMR 7: merrier
EIMT 8*: mimetite
EINP 7: ninepin, pennine (to target N)
EINT 8*: nineteen
EIPR 9**: pepperier
EIPS 8*: speisses (also speises, speiss if want fewer letters)
ELNS 9**: senseless (senselessness is too long to fit!)
ENUY 7: ennuyee (also ennuye if don't want 2nd E)
FILU 7: fulfill
GINZ 7: zigging, zinging (also gigging, ginning if don't want Z)
HISY 8*: sissyish
IRNT 9**: trinitrin
CIKN 12***: kinnikinnick (max length! also accepts kinnikinnik, kinnikinic, kinnikinnic...)
IORT 8*: trottoir (also riroriro if don't want T)

Useful or less obvious three-letter combos if you're struggling:
ABK 6: kabaka (also abaka, babka, kabab if don't want 2nd K)
ABN 6: banana
ACE 5: caeca
ACY 5: yacca
ACI 6: acacia
ACN 6: cancan
AEK 6: akeake
AHM 6: hammam
AHR 5: arrah, arrha
AIK 5: kaiak
AIL 6: alalia (also aalii if don't want 2nd L, ilial if don't want 2nd A
AIS 6: assais
AJN 5: jnana (anana also a choice if don't want to use J)
AKR 6: karaka (also karak, kara if don't want later letters)
ALM 6: mammal (to target M), mallam (even spread)
ALN 6: lallan
ALP 6: appall, palpal (also alapa if want 3rd A)
AMN 6: manana (to target A), mannan (to target N), also manna, namma
AMO 6: maomao
APY 6: papaya
ARU 5: aurar
ARY 5: array
ATO 6: tattoo
BER 6: berber (also beebee if prefer extra Es)
BHO 6: boohoo (booboo also a choice if don't want H)
BHU 6: hubbub
BIT 6: titbit
BIU 6: buibui
BLU 6: bulbul
BUY 5: bubby
CER 5: recce
CHI 6: chichi (also chich if don't want 2nd I
CHO 6: chocho
DEI 6: eddied (also deeded and didie are available)
DEO 6: dodded (deeded also a choice if don't want O)
DEP 6: peeped, pepped (deeded also a choice if don't want P)
DES 6: seeded
DET 6: detted
DHO 6: hoodoo
DIK 6: dikdik
DIL 5: dilli
DKO 6: koodoo
DMU 6: dumdum
EFT 6: effete
EHT 6: teethe
EIK 6: kiekie
EIR 6: eerier
EIT 6: tittie
EJR 6: jeerer
EKR 6: keeker, reeker
ENP 5: penne
ENV 6: venene
EOP 6: epopee
EPT 6: teepee
EPV 6: veepee (also peeve, veep if too many Es)
ERT 6: retree, teeter, terete, tetter
ESY 6: yesses
ETZ 6: tzetze
FIL 5: filii
GIR 6: grigri
GLO 6: googol (to target O), loglog (even spread)
GRU 6: grugru
HIS 5: shish
HMU 6: humhum (even spread), hummum (to target M)
HOL 6: holloo
HOP 6: hoopoo
HOR 6: hooroo
HRU 5: uhuru
IJN 5: jinni
IKN 5: kinin
IKO 5: kikoi
ILM 5: milli
ILN 5: linin
ILV 5: villi
IMN 5: minim
IMS 6: missis
IMX 5: immix
INP 6: pippin
INY 5: ninny
IOT 6: toitoi
IPT 5: pipit
IPU 6: piupiu
IPY 5: pippy
IRT 6: tirrit
IOS 6: sissoo
ITY 5: titty
ITZ 5: zizit
LOV 5: ovolo
LYS 5: slyly (avoids usual vowels)
MTU 6: mutuum
OMP 6: pompom

Useful or less obvious two-letter combos if you're struggling:
AB 4: abba, baba
AC 4: acca, caca
AD 4: adad, adda, dada
AF 4: faff
AG 4: gaga
AH 4: haha
AL 4: alla, lala, lall
AK 4: kaka
AP 4: papa
AR 4: rara, arar
AW 4: wawa
AY 4: yaya
BI 4: bibb, bibi
CE 4: ecce
CO 4: coco
DI 4: didi
DO 4: dodo
EF 3: eff
EH 4: hehe
EK 4: keek
EL 4: elle
EN 4: nene
EP 4: epee, peep, pepe
ET 4: teet, tete
FI 4: fifi (also handy to know 'iff' to avoid second I)
FU 4: fuff
GI 4: gigi
GO 4: gogo, goog
HO 4: hoho
HS 3: shh (handy to have a combo without vowel!)
IJ 4: jiji
IK 4: kiki
IL 4: lill
IM 4: mimi
IN 3: inn (handy you can double the N)
IP 4: pipi
IS 4: isis, sisi, siss
IT 4: titi
IX 3: xix (surprising)
IV 4: vivi
IW 4: wiwi
IZ 4: zizz
JU 4: juju
KO 4: kook
KU 4: kuku
LO 4: loll
LU 4: lull, lulu
MO 4: momo
MU 4: mumm
MY 3: mym (avoids usual vowels)
NO 4: noon
OP 4: poop
OS 4: soso
OT 4: otto, toot, toto
OY 4: yoyo
RU 4: ruru
SU 4: suss, susu
TU 4: tutu

As for the game review.... the problems with saving the high scores obviously disappointed me!! But the game idea is excellent: good variety of enemies and interesting tactical choices. Some things that don't really work so well:
- The game gets "samey" after a while. Once all the enemy types have appeared, you lose the sense of progression. Maybe some kind of in-game events can be added? Or some kind of target you can work towards? Just a random idea, but you might have a copy of the alphabet on-screen where all the letters you've used so far light up, and if you manage to use all 26 then you get some kind of bonus and the alphabet resets again. Or perhaps there is a way to complete the game and competition can be on time taken not just score?
- The game would be balanced more towards tactics and word knowledge, and less towards luck, if you could see the next set of letters you will receive. There would be even more interesting tactical choices if you had a special power that let you "hold" one of your current five letters in its position, so only the four other letters change next turn.
- Rather than just shooting enemies, there would be an extra tactical element if you could also shoot certain power-ups to gain hearts or immediate special power recharge. This would give a bit more flexibility using the special powers: you could use a power knowing you could recharge it again. Presently all the power-ups you gain are collected automatically when they reach the bottom of the screen - having others that pop up for one turn only would force players to make a choice about whether to bother collecting them or not.
- Later in the game you can get very crowded columns of enemies. It would be nice to give the player some options to deal with this, especially if there is a target like an eye (where hitting it in its vulnerable turn is important) hidden behind skeletons. Maybe a "laser" special power that penetrates through the entire column, causing one damage to each enemy (more if the letter is repeated or you use the 2x damage special power)?
- The word list is very poor: like someone else pointed out it accepts slurs, but it also is missing some common words (e.g. "hi", "bling", "meme", "strim", "spliff", "acai"), yet it also includes some incredibly rare or archaic words that aren't used in modern English ("wur", "wil", "ravar"). There can be inconsistencies accepting plurals of rare nouns or conjugations of rare verbs: "pind" is accepted (a verb meaning to enclose something), yet "pinds" (as in "he pinds") is not accepted. In fact lots of the words that are accepted do not even appear in online English dictionaries. It's also inconsistent about proper nouns - it accepts "Comox"(a Canadian indigenous people), "Jur" (an African language) and "LANta" (a Pennsylvanian public transit system) as well as many personal names and surnames (e.g. "Dion", "Cindi" and "Danni"), some place names (e.g. "Spain". "London") and even some "words" which are just Roman numerals. Yet many common technical abbreviations like NAND are not accepted. Better wordlists are available but some like the carefully curated Scrabble wordlists are under copyright. I know the maker of Wordle had to spend a long time to come up with a sensible wordlist too.
- Sometimes you have to use a particular letter, e.g. if you only have one vowel available. It's quite common to face unwinnable scenarios. A chicken might be above your only vowel twice in a row, so you can't use your letter swap the second time. Or a chicken appears behind a fire elemental, so you can't destroy the fire elemental without destroying the chicken.
- Sometimes the letters cannot be used to produce a meaningful word, beyond a couple of letters.

I think the last two points could be addressed by thinking both about how the enemies spawn and the random letters are chosen.

cool concept and the music and art are great!

Cute little game! I like the combination of tower defense with word/typing mechanics: that alone is already nice enough to keep my interest, but when you combine it with special abilities and diverse enemy variety and so on, it gets really complex in an interesting way! It's like, the game could've just been about always typing the biggest words, but when you factor in innocent chickens that you want to avoid, or maybe enemies that split, there's actually a lot of strategy involved in what is truly optimal beyond just the biggest words (but then you also need to factor in the bonus for using all letters: maybe its worth sacrificing a chicken for that!) Game is also just very juicy and charming with its general presentation too: well done!

I will admit, though, that parts of the game had me really confused. For example, there were plenty of times where the game allowed me to fire when the word I typed was seemingly gibberish. I'm giving you the benefit of the doubt that they were technically real words that I was typing, just unbeknownst to me, but still, weird stuff.

There's also the fact that I found it quite weird that there is no time limit: instead of the enemies coming down over time, they freeze in place until you make your move. Call me an armchair developer if you like, but I feel like this compromises the scoring system, since without any pressure, it just becomes a game of patience where anyone could take all the time in the world to make the most optimal choices, instead of being a game about skill, reactivity and improvisation. Maybe it was an intentional choice to make a more relaxed game, I guess (though if that were the case, you'd think that hurting chickens would only deprive you of an opporunity to get health, not immediately hurt you as well).

This was more fun than I expected :D