Cosmic Star Heroine is a throwback to early sprite-based RPGs with notably retro (though not low-quality) visuals and controls (directional buttons to move, enter to select, tab to bring up the character menu, and space to switch menu tabs). The two things that really stand out about it however are the combat system and general offhand irreverence in both the dialog and plot developments.
Combat is interesting as it’s made up of reusable abilities, rechargeable abilities, and limited abilities; reusables are generally weak attacks that can be used as much as you want, rechargeables can only be used once before you have to defend to recharge them, and limited abilities (granted by items and equipment) can normally only be used once per battle. Complicating things a bit is the Hyper Mode system, which gives every character a large strength boost every few turns (the intervals vary per character).
So for the greatest effectiveness in battle you have to plan out exactly when you’re going to use your strongest abilities and when you’re going to defend to recharge them since you certainly don’t want to be stuck having to defend on a Hyper-boosted turn. What saves this from becoming annoying is that not only does HP fully regenerate after each battle (meaning each battle effectively exists in a vacuum) but you(‘ll eventually) also have a large selection of abilities to pick and choose from; you don’t have to take the weaker abilities if you don’t want to.
Less of an unequivocal good thing is the style of humor, which is constantly present in everything from the character dialog to the item/enemy descriptions and borders on the 4th-wall breaking (there’s a side-mission which recreates part of Resident Evil 2). It’s basically a parody, with everything being a joke to some extent and plot developments often coming across as either random or blatantly contrived. So far it’s been very hit and miss, leaning a bit more toward ‘miss’ as of Chapter 8.
As for Starpoint Gemini Warlords… I couldn’t get into it. It’s very much like an enhanced Freelancer (which I loved at the time it was released), but I’ve long lost the ability to handle true space combat; the combination of 360° movement, throttling the combat speed, shield and light weapon energy usage, limited heavy weapon ammo, use of multiple skills, and a boarding minigame on top of it all is far more than I can comfortably keep track of.