I wanted to enjoy this film when I saw it at the cinema back then but (spoiler alert) the fact that he has a secret weapon ("Death Blossom") that destroys all the enemy ships in one go the entire film felt dumb. Why didn't the Rylan Star League use it themselves?
Because it was a prototype, just invented, that the lizard mechanic had been trying to get to work when their base was attacked.
it wasn't a "hidden reserve," it was a desperate gamble with an untested weapon system. The good guy's effort wasn't a military tactic, it was the suicide attack of defeated individuals spending their lives for any vengeance they could get. Success was unexpected.