Crimson Shadow is pretty much digital Dungeons and Dragons (seriously, everything is determined by dice, you obtain dice by performing special combos, etc.). The gameplay moves a bit slower than the standard RPG (every time you walk into a room, there's a bit of dialogue...and I mean every time), but it's still an interesting thing to play if you're into it. I haven't been able to beat it yet due to my inability to play RPGs efficiently (i.e. I suck), but it has a really unique style that you should check out.
Liberation Maiden, imagine it like Starfox. It's nice, fast paced, it's got animation from BONES (Ouran High School Host Club, Soul Eater, Full Metal Alchemist), superb voice acting, a bit of backstory, but the main game itself is 150 minutes max (there are five levels, and you can spend up to thirty minutes in them each). There are things you can unlock by performing hidden sidequests in every level and just doing a standard arcade mode and whatnot, but it's definitely worth a play. Also, there's J-Pop.
So, which one should you get? Entirely depends on what type of game you're craving at the moment. Crimson Shadow is a longer, indepth RPG, whereas Liberation Maiden is a shorter, fast paced free-roaming TPS.