Here is the full list of all 19 Plasma Puncher achievements.
Finish game on Hard Mode.
Kill 5 Spazzys in a single play.
Kill 25 enemies with Bomby's explosion in a single play.
Bounce 7 consecutive times on Goldy.
Kill 30 Spikys in a single play.
Collect 1000 Gold Particles in a single play.
Destroy 6 enemies with a single SUHA.
Obtain all Upgrades.
Kill 15 enemies with Hammer in a single play.
Kill 30 enemies with Rockets in a single play.
Kill 30 enemies with Tornado in a single play.
Kill 20 enemies with Drill in a single play.
Kill 15 enemies with Asteroids in a single play.
Kill 30 Bullys in a single play.
Kill 30 enemies without taking any hit.
Finish Game on HardCore mode.
Finish Game on Time Trial mode.
Connect 7 consecutive Stomp Attacks, without touching the ground.
Hit enemies using the Throw attack 30 times