Staying tuned - great find! Looks like it was released just shortly before you posted, so good on these guys for their vision spreading fast. At first I was confused how there were only 7 reviews on Steam.
Liking the Rastan style running animation with the interchangeable weapons.
The weapon system is really cool - each one has a magic attack you can use by breaking it. The magic can either be a buff for your character, an attack, or health boost. Weapons are also your currency for permanent upgrades to your mech. The game is appropriately tough on Normal for any old-school gamer who cut their teeth on Mega Man or Castlevania. It is a nice touch for those not as adept at action-platformers that they can change the difficulty on the stage select screen and not lose any progress if things get too hard. I'd say the pacing is about on par with the Bloodstained Curse of the Moon games - a bit slower like classic Castlevania but with a bit more mobility.
This game came out of nowhere, but I'm glad I stumbled upon it. There's too many 2D Metroidvanias in the indy space, so Panzer is actually a breath of fresh air. If I see another add for a "ZOMG CASTLEVANIA ORGY METROID GOODNESS LOVINGLY CRAFTED" nonsense I'll hurl.
I love that style game, but the market is crowded with them.
This is easily the best new 2D platformer I've played since The Messenger.