Genji Tsushin Agedama
For sometime now I have been a proponent of this criminally, oft ignored hidden gem in the PCE library. This game is based off an anime, and manga series of the same name. A "forced scroll" platformer (ala Monster Lair) with colorful graphics, quality control, and cool attacks.
You start with a typical peashooter of a weapon, but get power-ups of varying colors that add some uniqe attacks. Your special attacks vary by color, and also by how long you hold the button down (the colored gauge determines what attack is unleashed). Control is buttery smooth, and responsive. Graphically it's not a powerhouse, but still throws some very enjoyable scenes up, with a a decent amount of stage variety. Music is upbeat, and excellent chip tunage.
This is easily one of my favorite PCE games that I regularly return to. In my opinion a MUST OWN.
*Pictures & videos compliments of Sunteampaul @ The PC Engine Bible*