- POW difficulty adjustment (needs tuning, probably)
- Miners connecting, getting block template and mining (not full blocks yet)
- miners using multiple snow fields as needed
- Block DB, DB in general
- UTXO hashed Trie db
- Making snow fields for PoW
- PoW in general with proofs and verification
- blocks forming a chain
- transactions
- merkle root of transactions
- utxo root hash updates and validation
- Having a mempool and putting transactions into blocks
- lite client api (absolutely bare minimum works)
- p2p networking
- switching to best chain
- snow storms
- any sort of wallet (via lite client)
- UPNP ports
- onion/proxy support