The trailers are rather underwhelming. Pokemon Legends Arceus looks far better, just because of the different biomes and the nature aspect. Anyway, here are the confirmed Pokémons in the game:
Charmander
Charmeleon
Charizard
Pidgey
Pidgeotto
Pidgeot
Ekans
Arbok
Pikachu
Raichu
Bellsprout
Weepinbell
Victreebel
Onix
Kangaskhan
Staryu
Starmie
Pinsir
Magikarp
Gyarados
Eevee
Vaporeon
Jolteon
Flareon
Aerodactyl
Dratini
Dragonair
Dragonite
Chikorita
Bayleef
Meganium
Totodile
Croconaw
Feraligatr
Spinarak
Ariados
Pichu
Mareep
Flaaffy
Ampharos
Espeon
Umbreon
Steelix
Heracross
Houndour
Houndoom
Larvitar
Pupitar
Tyranitar
Ralts
Kirlia
Gardevoir
Sableye
Roselia
Swablu
Altaria
Absol
Bagon
Shelgon
Salamence
Budew
Roserade
Riolu
Lucario
Hippopotas
Hippowdon
Leafeon
Glaceon
Gallade
Tepig
Pignite
Emboar
Patrat
Watchog
Sandile
Krokorok
Krookodile
Trubbish
Garbodor
Emolga
Litwick
Lampent
Chandelure
Bunnelby
Diggersby
Fletchling
Fletchinder
Talonflame
Scatterbug
Spewpa
Vivillon
Litleo
Pyroar
Flabébé
Floette
Florges
Skiddo
Gogoat
Pancham
Pangoro
Furfrou
Espurr
Meowstic
Honedge
Doublade
Aegislash
Spritzee
Aromatisse
Swirlix
Slurpuff
Inkay
Malamar
Skrelp
Dragalge
Clauncher
Clawitzer
Sylveon
Hawlucha
Dedenne
Goomy
Sliggoo
Goodra
Klefki
Noibat
Noivern
Zygarde
