A few bugs I've noticed:
-if you use 'Q' to rotate, any attack going up (projectile traveling cardinal north) fails to apply backstab damage. Using 'E' or the 'rotate' button still applies backstab correctly, as does 'Q' when attacking an enemy left, right, or down from your character. I've only personally noticed this with the main character's Mind Blast and Cryoblast, but I assume it carries over to all characters (as I just noticed the same bug occurs in TRPG 2!).
-in the card game, there's a glitch(/exploit) when using Psy cards that target a minion. Clicking on the psy card twice, then clicking it twice again (instead of selecting the minion target) subtracts additional psy points. If you do this until you get the "You don't have enough psy points for this card" message, then target a minion, the card's effect happens as normal, but the card remains in your hand instead of being used up. If you discard cards to restore PsP, you can keep using the same Psy card.
-not sure what you could do about this, but in a battle, if you hover over an enemy with the cursor to display their health/attacks, click and hold the mouse, then drag it over to their attacks (and release), the enemy's frame remains displayed instead of switching back to your active character (I discovered this when I was trying to see what an enemy's attacks did). If you click on the enemy's attack buttons, you can get messages like "Ravinale Guard has no target" or "Not enough Psy Points." If you move your cursor outside of the attack frame, then back, it displays the active character's attacks, but still has the enemy's name (you can control the your character and attack as normal, but the name is bugged: "Ravinale Guard causes 19 damage with Mind Blast"). The attack frame returns to normal when you move the cursor over a different enemy/character or you end your turn. Not a big deal, but I once bugged it so my active character could move, but had "already attacked" that turn (and couldn't 'Undo' or use an attack--I don't remember how, though...it was probably Griffin, since both he and most enemies have 'Melee' and it doesn't use PsP).