As verbs the difference between slam and criticise
is that
slam is (ergative) to shut with sudden force so as to produce a shock and noise or
slam can be (card games) to defeat by winning all the tricks of a deal or a hand while
criticise is to evaluate (something), and judge its merits and faults.
As a noun slam
is (countable) a sudden impact or blow or
slam can be (obsolete) a type of card game, also called ruff and honours.