I've finally got to grips with DOTA well enough to try some different heroes.
Venomancer is my weapon of choice; with enough creeps serving as a distraction you can lay down about six Plague Wards next to a tower and take it down in a minute or so. His poison spray thing is great for whittling down enemy creep waves. He kind of sucks against other heroes though, unless he's part of a big push.
Lifestealer is my alternative. He just hops about like a monstrous frog and slaps things to death. High damage and decent attack speed combined with passive vampirism mean that with enough creeps to slaughter he can actually stand next to a tower with no net health loss. He struggles a bit with mana mid-game, but since his main power is just a straight attack speed buff it's not a big deal. In the event that he does get swamped, he can just Infest an enemy, wait for them to move away from danger and then burst out of their backside in a bloody explosion.
Nyx Assassin is a decent fun, but my God does he struggle with mana. I'm too dumb to know the item catalogue inside out, but I'm definitely going to try and find something like a more expensive Sage's Mask that will just straight-out improve his mana regen. His skills are decent fun - erupting spikes to send creeps flying, Vendetta to turn invisible and quickly backstab bruisers, and Mana Burn to incapacitate wizards - but I barely got an opportunity to use the latter two because the former consumed half my mana in one go.
Got plenty more to try, but new heroes don't take as long to learn as I thought they would, which is good.
EDIT:
Meanwhile, it's time for yet another trip to
Albie's Pretention Corner: Art Games Are, Like, Totally Art.
The Plan is very much more playable art than an artistic game, and I wouldn't say it's fun in any significant sense. Like many others, it's more an observation on the power of interactivity, allowing you to connect to an otherwise unrelatable protaganist in a short period of time unachieveable in other forms of media. It's not all that exciting, but worth a few minutes of your time to see the payoff of this at the end.