that can definitely be a problem for decks that use exclusively un-targetable creatures (burrowed/quinted), or just not many creatures at all like poison decks.
however keep in mind that i can usually blow up shields after a while, i'll get 2 to 3 turquoise nymphs out usually (they are 7/4), and any targetable creatures they do have can end up damaging themselves with the antimatter/liquid shadow combo. i find a lot of games come down to the last 5 cards but i'm usually able to get enough damage in if i successfully manage to establish control in the first place (with a quinted and sharded purple nymph primarily).
making it larger helps win more of those close deckout situations, but of course also reduces the consistency. maybe bumping to the 35 card range would be an improvement, and one nice reason to do that is to add a few forest pendulums. adrenaline synergizes nicely with both anti-matter and liquid shadow as well as the damage of the entropy and darkness nymphs (3). i'll give that a try, thanks.