Yeah, Shock Troopers is fantastic. I actually only played it last year for the first time and instantly fell in love with it. I'm pretty sure this is currently my favorite top-down Run n Gun game, dethroning KiKi KaiKai and Twinkle Tale. Not because it's necessarily better, but mostly because, mechanically, the combo of i-frame dodge rolls + strafing + Shinobi-style melee in close range combat hits all the right buttons for me.
To stay on topic, barring a shitty execution, I generally feel that i-frame dodging, parry + counter, wall-jumping, double jump, grappling hooks and downward melee attacks (especially when you can bounce off the enemy, a la Zelda II and Monster World IV, and "chain" your attacks, either by repeating the process or by slashing while still off the ground) are inherently awesome, extremely satisfying, mechanics. It would actually be kinda cool to have a game that tries to combine most of these mechanics while performing the, admittedly, gargantuan task of a) utilizing them consistently throughout the game and b) not being unbalanced. Maybe even a scoring system that rewards you for staying on the move, playing with style and successfully chaining the mechanics in various situations throughout the game.
This one can be tricky because, when things are not well-thought-out, you can easily end up with monstrosities (see traditional scrolling shooters that have inertia, most likely, only because...that's how things work in real life

). However, when implemented well, physics-based gameplay within an arcade framework and "ethos" can do wonders for a game. From action games, like Umihara Kawase and Sub-Terrania, to arcade racers like Wave Race 64 and WipEout, arcade-style physics-based gameplay can be immensely satisfying and rewarding to master.