Lands (20) Spells (40) There was a real shortage of playable lifegain, and the format was extremely fast
The second set also has some pretty interesting cards, such as Seymor Flux , and a spell that may be the perfect answer to the Jumbo Cactuar Extermination
There is plenty of life gain not on this list that still gets some niche cube play as lifegain cards and also plenty of regular cube cube cards that get play but not really as any sort of life gain thing
The same is true for first strike, double strike, deathtouch, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance
Hardened Scales is a great way to bolster the +1/+1 counter theme, and ways to play lands from outside of your hand like Radha, Heart of Keld can ensure even more landfall triggers