Pokémon Crystal: Just started — no badges

What opens up at this point in the game, and everything you can catch by now that you couldn't before.

Now usable

• Gift
• In-game trade
• Grass (morning)
• Grass (night)
• Gift egg
• Grass
• Grass (swarm)
• Static encounter
• Grass (swarm, morning)
• Grass (swarm, night)
• Squirt Bottle
• Poké Flute
• Roaming (land)

Newly reachable

Newly catchable (140)

AbraAerodactylArbokAriadosBellsproutButterfreeCaterpieCelebiChanseyChikoritaClefairyCleffaCuboneCyndaquilDelibirdDiglettDittoDodrioDoduoDonphanDratiniDrowzeeDugtrioDunsparceEeveeEkansElectabuzzElectrodeElekidEnteiFarfetch’dFearowFurretGastlyGeodudeGligarGloomGolbatGranbullGravelerGrimerGrowlitheGyaradosHaunterHo-OhHoothootHoppipHoundourHypnoIgglybuffJigglypuffJynxKadabraKakunaKangaskhanKoffingKrabbyLaprasLarvitarLedianLedybaLickitungLugiaMachokeMachopMagbyMagnemiteMagnetonMarillMarowakMeowthMetapodMiltankMr. MimeMukMurkrowNatuNidoran♀Nidoran♂NidorinaNidorinoNoctowlOddishOnixParasPersianPhanpyPichuPidgeottoPidgeyPikachuPoliwagPoliwhirlPonytaPsyduckQuagsireRaikouRapidashRaticateRattataSandshrewSandslashSeelSentretShuckleSkarmorySkiploomSlowpokeSlugmaSmeargleSmoochumSneaselSnorlaxSnubbullSpearowSpinarakStantlerSudowoodoSuicuneSunkernSwinubTangelaTaurosTeddiursaTogepiTotodileTyrogueUnownUrsaringVenomothVenonatVoltorbWeedleWeepinbellWeezingWobbuffetWooperXatuYanmaZubat

TMs you can now pick up

• TM02 Headbutt — Ilex Forest
• TM03 Curse — Celadon City
• TM04 Rollout — Route 35
• TM05 Roar — Route 32
• TM07 Zap Cannon — Power Plant
• TM08 Rock Smash — Route 36
• TM09 Psych Up — Location not compiled for this game yet
• TM10 Hidden Power — Lake of Rage
• TM11 Sunny Day — Radio Tower — 3F
• TM12 Sweet Scent — Route 34 — Ilex Forest Gate
• TM13 Snore — Dark Cave — Blackthorn Entrance (and 1 more)
• TM14 Blizzard — Goldenrod City
• TM15 Hyper Beam — Celadon City
• TM17 Protect — Location not compiled for this game yet
• TM18 Rain Dance — Slowpoke Well
• TM20 Endure — Burned Tower
• TM21 Frustration — Goldenrod City
• TM22 Solar Beam — Route 27
• TM25 Thunder — Goldenrod City
• TM27 Return — Goldenrod City
• TM28 Dig — National Park
• TM29 Psychic — Location not compiled for this game yet
• TM32 Double Team — Celadon City
• TM33 Ice Punch — Location not compiled for this game yet
• TM34 Swagger — Lighthouse
• TM35 Sleep Talk — Goldenrod City
• TM36 Sludge Bomb — Route 43 — Gate
• TM37 Sandstorm — Route 27 — Sandstorm House
• TM38 Fire Blast — Goldenrod City
• TM39 Swift — Union Cave — B1F
• TM40 Defense Curl — Mt. Mortar
• TM41 ThunderPunch — Location not compiled for this game yet
• TM42 Dream Eater — Viridian City
• TM43 Detect — Lake of Rage
• TM44 Rest — Ice Path — B2F Blackthorn Side
• TM46 Thief — Mahogany Town
• TM47 Steel Wing — Rock Tunnel — 1F (and 1 more)
• TM48 Fire Punch — Location not compiled for this game yet
• TM50 Nightmare — Route 31
• HM01 Cut — Ilex Forest
• HM02 Fly — Cianwood City
• HM03 Surf — Ecruteak City
• HM04 Strength — Olivine City
• HM05 Flash — Sprout Tower
• HM06 Whirlpool — Mahogany Town
• HM07 Waterfall — Ice Path — 1F

Bosses around here