They mostly focuses on full screen pressure, frame traps & trying to catch people grazing through projectiles. Both games let you block incorrectly but it punishes the meter you use for bullets, specials & incorrect blocks.
IAMP is far more competitive than SWR but has a very small community right now. If you actually play other fighting games seriously, try this one.
SWR/Hisoutensoku is good if you want a casual fighter that is easier to get into. Has about twice as many characters but plays a lot differently from IAMP. Flight is a pretty major aspect to this game and your melee options are limited, both turn a lot of people off to this game. The more popular of the two, but the community is still fairly small.