That’s, an exceedingly harsh way to put it, but a way.
Do keep in mind this is a Demo, it is very likely for the unfavorable type matchup against Guy to change more as the game further releases. (Admittedly, in the current state, I believe the current counterplay is to have known to train up Paras to stun spore and allow you to get hits in, but as abilities aren’t shown in full that may be difficult to parse it’d help- let alone to know to do that. Porygon can take a hit if it was full hp, going for a para with Thundershock [I know…] could work, and I haven’t done any testing with Elgym (They’re in the part of route 1 with the trainers, seemingly pretty rare- but there. )
The movesets themselves? Flamethrower is set to change, fire spin and Flame charge are suitable for a first gym (FRLG Brock’s onix had rock tomb, a 50 base power move that lowered speed, flame charge isn’t farfetched, especially since Porygon can win the 1v1 vs peppino after fighting tentacruel if it doesn’t get scald burned). Willow and scald may be a bit suspect, but considering the mons packing it are under leveled (Tentacruel is 6 under cap, Peppino is 4) it’s not too pressing (Porygon also helps here, especially if you have Oddish or Bounsweet chip down cruel), I don’t believe it to be overwhelming- especially as expected levels are higher for future releases. Flamethrower has already been addressed.
I don’t actually KNOW Maractus’ moveset beyond flamethrower, so I can’t say much there- but I believe that for a first gym, with a few adjustments, flamethrower as planned being subbed out and potentially scald being switched for say, water pulse (Even if Scald is thematically appropriate for a fire gym) or a grass type move (for stab and to counter water/ground types in the future), it’d be beyond solid. [Edit: I forgot. Steel Beam. I think that feels a little out of place and- more often than not, just results in Peppino KOing itself for no reason if the AI chooses it on the low health roulette (if this is based on Gen 3) Metal claw could work as a replacement, should you want a steel type move that works a bit better.]
Still though, excellent feedback! Just a little harshly worded but, you got to what you meant incredibly quickly and provided reasons as to why.
(And- apologies from dissapearing from all circles.)