Interesting platformer, it's fun. Corny story and voice acting but about what you would expect for a "shonen" hot-blooded plotline. The animations are made with love.
In terms of its value as an action game, maybe I've been spoilt by crisp responsive games like Monster Hunter, Street Fighter etc. enough that I'm not the best fan of animation delays. The aiming and movement are cursor-dependent and that takes some getting used to.
But I think people will enjoy this game if they regard this as a puzzle to solve and not like an Action RPG where you just want to kill lots of enemies without being stopped.
That said, the Survival Mode that unlocks after Story Mode is even more fun than the story mode in my opinion, it scratches that SD Gundam mech development and customization itch by letting you play around with all of the other mass-produced mechs featured in the story, and some of the later unlocks are hilariously broken. Only downside is that there might be some bugs that prevent progress and you have to end your run early.
In terms of story mode gameplay, Hardcore Mecha with its delayed animations, hit flinches, and potential for the level design to chain-stun you through a combination of environment hazards and enemy mecha attack pushbacks means that the emphasis is on careful positioning at range. You're not that rewarded for using melee unless you've singled out an enemy from a pack, and if you receive hitstun it's common to get caught and punished by enemies across the screen for a brutal punish. So use the block button judiciously, and dash through enemies as needed to avoid getting cornered.